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Objective: To explore if experience with hearing aid (HA) amplification affects speech-evoked cortical potentials reflecting comprehension abilities., Design: N400 and late positive complex (LPC) responses as well as behavioural response times to congruent and incongruent digit triplets were measured. The digits were presented against stationary speech-shaped noise 10 dB above individually measured speech recognition thresholds. Stimulus presentation was either acoustic (digits 1-3) or first visual (digits 1-2) and then acoustic (digit 3)., Study Sample: Three groups of older participants ( N  = 3 × 15) with (1) pure-tone average hearing thresholds <25 dB HL from 500-4000 Hz, (2) mild-to-moderate sensorineural hearing loss (SNHL) but no prior HA experience, and (3) mild-to-moderate SNHL and >2 years of HA experience. Groups 2-3 were fitted with test devices in accordance with clinical gain targets., Results: No group differences were found in the electrophysiological data. N400 amplitudes were larger and LPC latencies shorter with acoustic presentation. For group 1, behavioural response times were shorter with visual-then-acoustic presentation., Conclusion: When speech audibility is ensured, comprehension-related electrophysiological responses appear intact in individuals with mild-to-moderate SNHL, regardless of prior experience with amplified sound. Further research into the effects of audibility versus acclimatisation-related neurophysiological changes is warranted.

Objective: To investigate the effects of previous occupational noise exposure in older adults with hearing loss on (1) audiometric configuration and acoustic reflex (AR) thresholds and (2) self-reported hearing abilities and hearing aid (HA) effectiveness., Design: A prospective observational study., Study Sample: The study included 1176 adults (≥60 years) with bilateral sensorineural hearing loss. Pure-tone audiometry, AR thresholds, and responses to the abbreviated version of the Speech, Spatial, and Qualities of Hearing Scale (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaire were obtained, along with information about previous occupational noise exposure., Results: Greater occupational noise exposure was associated with a higher prevalence of steeply sloping audiograms in men and women and a 0.32 (95% CI: -0.57; -0.06) scale points lower mean SSQ12 total score among noise-exposed men. AR thresholds did not show a significant relation to noise-exposure status, but hearing thresholds at a given frequency were related to elevated AR thresholds at the same frequency., Conclusions: A noise exposure history is linked to steeper audiograms in older adults with hearing loss as well as to poorer self-reported hearing abilities in noise-exposed men. More attention to older adults with previous noise exposure is warranted in hearing rehabilitation.

Objective: To investigate retrospectively the frequency of usage of bimodal stimulation among cochlear implant (CI) users, as well its clinical benefit relative to unilateral use., Design: All subjects had been monitored with the clinical Minimal Outcome Measurements test battery., Study Samples: 103 adults with bilateral postlingual profound sensorineural hearing loss and unilateral CI use were extracted from the local database. These were divided into two groups: those who only used a CI and those who used bimodal stimulation., Results: The preoperative contralateral residual hearing in the bimodal group was significantly better than that of the CI-only group. In both groups, speech perception in quiet and in noise improved after CI, with no significant difference between postoperative unimodal conditions. For the bimodal group, an additional significant improvement was found for the bimodal condition compared to the unimodal., Conclusion: Given the observed auditory benefit of bimodal stimulation in comparison to unimodal stimulation and given the finding that degree of residual hearing is not correlated with bimodal benefits, it is recommended to encourage CI recipients to continue contralateral HA use after CI. As a result of expanding CI criteria worldwide, the population of bimodal users is expected to grow in the near future.

Objective: A long-standing observation is that the Mismatch Response (MMR) has the potential to offer a clinically feasible index of sound discrimination. However, findings that positively identify MMRs at the individual level have been mixed, even for those who are normally hearing and who can discriminate sounds behaviourally. This complicates interpretation when an MMR is not observed. The objective of this study was to determine the reliability of the MMR using an optimised paradigm and a range of stimuli relevant to audiological applications in relation to objective verification of hearing aid fittings., Design: MMRs were measured using an optimised 3-deviant paradigm in response to a range of sounds designed for aided and unaided sound field assessments, including complex tones (CTs) and speech-like signals., Study Sample: Seventeen normally hearing adults (18-56 years)., Results: The most robust MMRs were recorded in response to CTs; responses were positively identified in 50 out of 51 instances (98%), assessed via objective Hotelling's T 2 bias-free statistical analyses., Conclusions: The results indicate that CTs in conjunction with optimised recording and analysis parameters offer the potential to elicit robust MMRs, supporting future utilisation of MMRs for clinical audiological applications.

Objective: This study aimed to analyse outcomes with hearing aid (HA) use and to determine whether common audiological tests, including pure-tone audiometry or word recognition test, correlate with HA wearers' subjective benefit., Design: A retrospective chart review., Study Sample: A total of 129 patients who adopted new HAs between January 2011 and December 2018 were enrolled. Outcome measures including pure tone thresholds, word recognition score (WRS), and self-reported questionnaires were obtained 1, 4, and 12 months post fit., Results: The mean aided threshold and WRS at each post-fit visit significantly improved from the unaided condition. Self-reported outcomes confirmed by the Hearing Handicap Inventory for the Elderly (HHIE) scores significantly improved compared to the unaided condition at 1- and 4-month follow-up. Results of the regression analysis indicated that the aided WRS score is a significant factor at all post-fit visits that explains less than 10% of the variance in HHIE scores., Conclusions: Aided WRS is the factor most associated with subjectively reported HA outcomes, both in the short- and long term. Therefore, aided WRS should be considered as a useful tool for evaluating HA benefits, even after the prolonged use of HAs.

Objective: The aim of this study was to determine whether the differences in insertion gains from the first fit to generic prescriptions of hearing aids can predict the self-reported hearing aid (HA) outcomes for first-time and experienced HA users., Design: This was a prospective observational study., Study Sample: The study included 885 first-time and 330 experienced HA users with a valid real-ear measurement on both ears and answers to the abbreviated version of the Speech, Spatial, and Quality of Hearing (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaires., Results: K -means clustering of gain differences between individual real-ear insertion gain to three generic gain prescriptions (NAL-NL2, NAL-RP, and one-third gain rules) was performed. The gain difference at higher frequencies generally differentiated the clusters. The experienced users in the cluster with fittings closest to NAL-NL2 and NAL-RP prescription were found to exhibit a higher IOI-HA Factor 1 score (representing the overall benefit of the hearing aid use). The gain differences to generic prescription did not affect other self-reported outcomes for first-time and experienced HA users., Conclusion: The experienced HA users with minimal gain deviations from generic prescriptions reported better self-perceived benefits than users with larger deviations. However, this was not apparent in first-time users.

Objective: This study investigated the effects of different adjustment criteria and sound scenes on self-adjusted hearing-aid gain settings. Self-adjusted settings were evaluated for speech recognition in noise, perceived listening effort, and preference., Design: This study evaluated a semi-supervised self-adjustment fine-tuning procedure that presents realistic everyday sound scenes in a laboratory environment, using a two-dimensional user interface, and enabling simultaneous changes in amplitude and spectral slope. While exploring the two-dimensional space of parameter settings, the hearing-aid users were instructed to optimise either listening comfort or speech understanding., Study Sample: Twenty experienced hearing aid users (median age 69.5 years) were invited to participate in this study., Results: Adjustment criterion and sound scenes had a significant effect on preferred gain settings. No differences in signal-to-noise ratios required for 50% speech intelligibility or in the perceived listening effort were observed between the adjusted settings of the two adjustment criteria. There was a preference for the self-adjusted settings over the prescriptive first fit., Conclusions: Listeners could reliably select their preferred gains to the two adjustment criteria and for different speech stimuli.

Objective: The objective of this study was to determine the prevalence, risk factors, and audiological characteristics of auditory neuropathy spectrum disorder (ANSD) in the pediatric population., Design: A retrospective review of medical charts was conducted for children visiting two hospitals in Saudi Arabia., Study Sample: Medical records of 1025 patients with sensorineural hearing loss (SNHL) were reviewed. We analyzed the databases for results of audiological examinations, risk factors, and outcomes of intervention including hearing aid (HA) and cochlear implantation (CI)., Results: Out of 1025 children with SNHL, 101 patients (9.85%) were identified to have ANSD. Audiological characteristics of the ANSD group revealed a severe-to-profound degree of hearing loss, all showed type A tympanogram and absent reflexes, absent auditory brainstem response (ABR) findings with present cochlear microphonic while otoacoustic emissions were absent in 54.5% of patients. The most prevalent risk factors for ANSD in this group were family history of hearing loss, consanguinity, hyperbilirubinemia, and low birth weight. Pure tone and speech detection thresholds improved significantly with CI compared to HA use in this sample of patients with ANSD., Conclusion: This study shows that ANSD is not extremely rare among Saudi children with severe to profound hearing loss, with a prevalence of 9.85%.

Objective: Whether hearing aid use in older adults modifies speech perception over time is not clear. To address this question, we systematically reviewed studies in which older first-time hearing aid users and controls were followed over time., Design: The review was pre-registered in PROSPERO and performed in accordance with the statement on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The question, inclusion and exclusion criteria were defined using the Population, Intervention, Control, Outcomes and Study design (PICOS) framework. Studies with no controls, studies in which participants and controls were tested at only one-time point, with no follow-up and no pre-fitting measures, or when outcome measures did not include speech measures, were excluded., Study Sample: 6113 studies were screened, out of which 12 studies, published between 1996 and 2021, met the inclusion and exclusion criteria and were included in the final review., Results: 9 of the 12 studies found evidence for amplification-induced auditory plasticity in older adults, expressed in improved speech perception., Conclusions: The results suggest amplification-induced improvements in speech perception over time, but findings should be interpreted with caution because overall improvements were small, and the studies' quality was moderate.

Objectives: To investigate the difference in outcome measures and drivers of user preference between premium and entry-level hearing aids using group concept mapping., Design: A single-blind crossover trial was conducted. Aided behavioural outcomes measured were loudness rating, speech/consonant recognition, and speech quality. Preference between hearing aids was measured with a 7-point Likert scale. Group concept mapping was utilised to investigate preference results. Participants generated statements based on what influenced their preferences. These were sorted into categories with underlying themes. Participants rated each statement on a 5-point Likert scale of importance., Study Sample: Twenty-three adult participants (mean: 62.4 years; range: 24-78) with mild to moderately severe bilateral SNHL (PTA 500-4000 Hz > 20 dB HL)., Results: A total of 83 unique statements and nine distinct clusters, with underlying themes driving preference, were generated. Clusters that differed significantly in importance between entry-level and premium hearing aid choosers were: Having access to smartphone application-based user-controlled settings, the ability to stream calls and music, and convenience features such as accessory compatibility., Conclusion: This study has identified non-signal-processing factors which significantly influenced preference for a premium hearing aid over an entry-level hearing aid, indicating the importance of these features as drivers of user preference.

Objective: This study examined the accuracy of hearing aid output to DSL v5.0 Child targets in a group of children who wear hearing aids, and the impact on their auditory outcomes., Design: For each participant, the output of the initial hearing aid fitting was compared to DSL v5.0 Child prescriptive targets and again after the fitting was adjusted using coupler-based verification and RECD measures. Outcomes for initial and adjusted fittings were examined using the Speech Intelligibility Index (SII), Parent's Evaluation of Aural/Oral Performance of Children (PEACH) rating scale, and speech perception tests in quiet and noise., Study Sample: Sixty-eight children aged 3 months to 17 years with moderate to profound hearing loss participated in the study., Results: Fit-to-targets improved significantly after hearing aids were adjusted to match targets to within 5 dB RMSE. Adjusted hearing aids provided increased aided audibility compared to initial fittings and resulted in improved speech perception scores and parent-reported hearing performance. Fifty percent of the children aged 6 to 17 years preferred their adjusted fitting compared to 10% who preferred their initial fitting., Conclusions: Improvement in fit-to-target to a validated paediatric prescriptive formula using best practice procedures can result in improved auditory outcomes and possible self-reported satisfaction.

Objective: To objectively evaluate acoustic sensitivity of the implanted microphone, and maximum stable gain of a totally implantable active middle ear implant., Design: Prospective, single centre evaluation., Study Sample: Fourteen adult patients., Results: Microphone sensitivity is approx. 10 dB lower than an externally worn conventional hearing aid, at frequencies up to 4000 Hz, and substantially lower at higher frequencies. The masking level due to microphone noise, which determines the softest test tones that can be detected, is estimated at &lt;20 to &lt;30 dB HL up to 1000 Hz, and &lt;40 dB HL at higher frequencies. Maximum stable effective gain is the maximum amplification achievable without causing feedback whistling. In sensorineural hearing loss (SNHL) cases, it is 30-40 dB at frequencies up to 2000 Hz, allowing to compensate for even the maximum recommended hearing loss (60-70 dB HL). In both SNHL and mixed hearing loss (MHL) cases, maximum stable effective gain is lower (+20 to -30 dB) around 3000-6000 Hz., Conclusions: Microphone sensitivity is high enough to achieve aided thresholds of 20-40 dB HL. A strong correlation between actuator coupling efficiency and maximum stable effective gain implies that any effort to improve actuator efficiency should also increase the available gain.

Objective: This study investigated if individual preferences with respect to the trade-off between a good signal-to-noise ratio and a distortion-free speech target were stable across different masking conditions and if simple adjustment methods could be used to identify subjects as either "noise haters" or "distortions haters"., Design: In each masking condition, subjects could adjust the target speech level according to their preferences by employing (i) linear gain or gain at the cost of (ii) clipping distortions or (iii) compression distortions. The comparison of these processing conditions allowed investigating the preferred trade-off between distortions and noise disturbance., Study Sample: Thirty subjects differing widely in hearing status (normal-hearing to moderately impaired) and age (23-85 years)., Results: High test-retest stability of individual preferences was found for all modification schemes. The preference adjustments suggested that subjects could be consistently categorised along a scale from "noise haters" to "distortion haters", and this preference trait remained stable through all maskers, spatial conditions, and types of distortions., Conclusions: Employing quick self-adjustment to collect listening preferences in complex listening conditions revealed a stable preference trait along the "noise vs. distortions" tolerance dimension. This could potentially help in fitting modern hearing aid algorithms to the individual user.

Objective: Conventional directional hearing aid microphone technology may obstruct listening intentions when the talker and listener walk side by side. The purpose of the current study was to evaluate hearing aids that use a motion sensor to address listening needs during walking., Design: Each participant completed two walks in randomised order, one walk with each of two hearing aid programs: (1) conventional beamformer adaptation that activated an adaptive, multiband beamformer in loud environments and (2) motion-based beamformer adaptation that activated a pinna-mimicking microphone setting when walking was detected. Participants walked along a pre-defined track and completed tasks assessing speech understanding and environmental awareness., Study Sample: Participants were 22 older adults with moderate-to-severe hearing loss and experience using hearing aids., Results: More participants preferred the motion-based than conventional beamformer adaptation for speech understanding, environmental awareness, overall listening, and sound quality ( p <  0.05). Measures of speech understanding ( p  < 0.01) and localisation of sound stimuli ( p  < 0.05) were significantly better with motion-based than conventional beamformer adaptation., Conclusions: The results suggest that hearing aid users can benefit from beamforming that uses motion sensor input to adapt the signal processing according to the user's activity. The real-world setup of this study had limitations.

Objective: The purpose of the study was to examine the effects of symmetrical and asymmetrical directional microphone settings on speech recognition, localisation and microphone preference in listening conditions with on- and off-axis talkers., Design: A within-subjects repeated-measure evaluation of three hearing aid microphone settings (bilateral omnidirectional, bilateral directional, asymmetrical directional) was completed in a moderately reverberant laboratory. An exploratory analysis of the potential relationship between microphone preference and unaided measures was also completed., Study Sample: Twenty adult listeners with mild to moderately severe bilateral hearing loss participated., Results: The directional and asymmetric microphone settings resulted in equivalent benefits for sentence recognition in noise, word recall, and localisation speed regardless of the speech loudspeaker location (on- or off-axis). However, localisation accuracy was significantly worse with the asymmetric fitting than the directional setting when speech was presented from the rear hemisphere. Listeners who always preferred directional microphones had significantly poorer unaided speech recognition than those who preferred the omnidirectional setting for one or more listening condition., Conclusions: Benefits from directional and asymmetric processing were small in the current study, but generally similar to each other. Unaided speech recognition in noise performance may have utility as a clinical predictor of preference for directional processing.

Objective: The purpose of the present study was to examine the effects of NLFC fitting in hearing aids and auditory acclimatisation on speech perception and sound-quality rating in hearing-impaired, native Mandarin-speaking adult listeners. Design: Mandarin consonant, vowel and tone recognition were tested in quiet and sentence recognition in noise (speech-shaped noise at a +5 dB signal-to-noise ratio) with NLFC-on and NLFC-off. Sound-quality ratings were collected on a 0-10 scale at each test session. A generalised linear model and correlational analyses were performed. Study sample: Thirty native Mandarin-speaking adults with moderate-to-severe sensorineural hearing loss were recruited. Results: The hearing-impaired listeners showed significantly higher accuracy with NLFC-on than with NLFC-off for consonant and sentence recognition and the recognition performance improved with both NLFC-on and off as a function of increased length of use. The satisfaction score of sound-quality ratings for different types of sounds significantly increased with NLFC-on than with NLFC-off. The speech recognition results showed moderate to strong correlation with the unaided hearing thresholds. Conclusion: For native Mandarin-speaking listeners with hearing loss, the NLFC technology provided modest but significant improvement in Mandarin fricative and sentence recognition. Subjectively, the naturalness and overall preference of sound-quality satisfaction judgement also improved with NLFC.

Objective: For a group of bimodal subjects with moderate to severe hearing loss contralateral to the cochlear implant (CI), the bimodal benefit of the hearing aid (HA) gain prescriptions DSL v5.0, NAL-NL2 and the recipients' own gain setting were assessed. Design: Speech perception in quiet and in noise as well as self-reported ratings of benefit were determined for all three gain-settings. Speech tests were performed in the bimodal, the HA alone and the CI alone condition. The bimodal benefit was assessed for each prescription as the difference score of the bimodal condition and the better ear. Study Sample: Twenty adults with post-lingual hearing loss. Results: Speech perception with DSL v5.0 was significantly higher compared to NAL-NL2 and the own prescription in both quiet and noise. The median bimodal benefit was highest for DSL v5.0 with an average of 15 percentage points for both words in quiet and sentences in noise. Conclusions: DSL v5.0 and NAL-NL2 are both suitable for HA fitting in bimodal users. For subjects with moderate to severe hearing loss and HA experience contralateral to the implanted side, DSL v5.0 may provide better speech perception and bimodal benefit.

Objective: The aim of this study was to examine how background noise and hearing aid experience affect the robust relationship between working memory and speech recognition. Design: Matrix sentences were used to measure speech recognition in noise. Three measures of working memory were administered. Study sample: 148 participants with at least 2 years of hearing aid experience. Results: A stronger overall correlation between working memory and speech recognition performance was found in a four-talker babble than in a stationary noise background. This correlation was significantly weaker in participants with most hearing aid experience than those with least experience when background noise was stationary. In the four-talker babble, however, no significant difference was found between the strength of correlations between users with different experience. Conclusion: In general, more explicit processing of working memory is invoked when listening in a multi-talker babble. The matching processes (cf. Ease of Language Understanding model, ELU) were more efficient for experienced than for less experienced users when perceiving speech. This study extends the existing ELU model that mismatch may also lead to the establishment of new phonological representations in the long-term memory.

Objective: To assess the speech perception benefits of binaural streaming technology for bilateral hearing aid users in two difficult listening conditions., Design: Two studies were conducted to compare hearing aid processing features relating to telephone use and wind noise. Speech perception testing was conducted in four different experimental conditions in each study., Study Sample: Ten bilaterally-aided children in each study., Results: Significant improvements in speech perception were obtained with a wireless feature for telephone use. Significant speech perception benefits were also obtained with wireless hearing aid features when listening to speech in simulated wind noise., Conclusions: Binaural signal processing algorithms can significantly improve speech perception for bilateral hearing aid users in challenging listening situations.

Clinicians have long used self-report methods to assess hearing aid benefit. However, there are fewer data as to whether self-report instruments can be used to compare differences between signal processing settings. This study examined how self-perceived performance varied as a function of modifications in signal processing using two self-report measures. Data were collected as part of a double-blind randomised crossover clinical trial. Participants were fit with two fittings: mild processing (slow time constants, disabled frequency lowering) and strong processing (fast time constants, frequency lowering enabled). The speech, spatial, and qualities of hearing (SSQ) questionnaire and the Effectiveness of Auditory Rehabilitation (EAR) questionnaire were collected at multiple time points. Older adults with sensorineural hearing loss who had not used hearing aids within the previous year participated (49 older adults were consented; 40 were included in the final data analyses). Findings show that listeners report a difference in perceived performance when hearing aid features are modified. Both self-report measures were able to capture this change in perceived performance. Self-report measures provide a tool for capturing changes in perceived performance when hearing aid processing features are modified and may enhance provision of an evidence-based hearing aid fitting.

Objectives: Model-based hearing aid development considers the assessment of speech recognition using a master hearing aid (MHA). It is known that aided speech recognition in noise is related to cognitive factors such as working memory capacity (WMC). This relationship might be mediated by hearing aid experience (HAE). The aim of this study was to examine the relationship of WMC and speech recognition with a MHA for listeners with different HAE., Design: Using the MHA, unaided and aided 80% speech recognition thresholds in noise were determined. Individual WMC capacity was assed using the Verbal Learning and Memory Test (VLMT) and the Reading Span Test (RST)., Study Sample: Forty-nine hearing aid users with mild to moderate sensorineural hearing loss divided into three groups differing in HAE., Results: Whereas unaided speech recognition did not show a significant relationship with WMC, a significant correlation could be observed between WMC and aided speech recognition. However, this only applied to listeners with HAE of up to approximately three years, and a consistent weakening of the correlation could be observed with more experience., Conclusions: Speech recognition scores obtained in acute experiments with an MHA are less influenced by individual cognitive capacity when experienced HA users are taken into account.

Objective: Loudness perception of binaural broadband signals, e.g. speech shaped noise, shows large individual differences using frequency-dependent amplification which was adjusted to restore the loudness perception of monaural narrowband signals in hearing-impaired (HI) listeners. To better understand and quantify this highly individual effect, loudness perception of broadband stimuli consisting of a number of spectrally separated narrowband components which where individually adjusted to equal loudness is of interest., Design: Based on categorical loudness scaling, the loudness of an equal categorical loudness noise (ECLN) consisting of six third-octave noises was assessed. For loudness categories "medium" und "very loud" the required narrowband loudness was analysed., Study Sample: Nine normal-hearing (NH) and ten HI listeners., Results: HI listeners showed lower narrowband loudness values compared to NH listeners, indicating an increased spectral loudness summation. More than 50% of the HI listeners showed higher binaural spectral loudness summation compared to NH listeners. The amount of binaural spectral loudness summation was highly correlated (r 2  = 0.92) with the loudness level at "very loud" of aided speech shaped noise., Conclusions: The suggested ECLN measurement is suited to assess individual (binaural) broadband loudness in aided conditions, providing valuable information for hearing-aid fitting.

Objective: The purpose of this study was to evaluate the reliability and validity of four subjective questions related to listening effort. A secondary purpose of this study was to evaluate the effects of hearing aid beamforming microphone arrays on word recognition and listening effort., Design: Participants answered subjective questions immediately following testing in a dual-task paradigm with three microphone settings in a moderately reverberant laboratory environment in two noise configurations. Participants rated their: (1) mental work, (2) desire to improve the situation, (3) tiredness, and (4) desire to give up. Data were analysed using repeated measures and reliability analyses., Study Sample: Eighteen adults with symmetrical sensorineural hearing loss participated., Results: Beamforming differentially affected word recognition and listening effort. Analysis revealed the same pattern of results for behavioural listening effort and subjective ratings of desire to improve the situation. Conversely, ratings of work revealed the same pattern of results as word recognition performance. Ratings of tiredness and desire to give up were unaffected by hearing aid microphone or noise configuration., Conclusions: Participant ratings of their desire to control the listening situation appear to reliable subjective indicators of listening effort that align with results from a behavioural measure of listening effort.

Objective: Binaural cues such as interaural level differences (ILDs) are used to organise auditory perception and to segregate sound sources in complex acoustical environments. In bilaterally fitted hearing aids, dynamic-range compression operating independently at each ear potentially alters these ILDs, thus distorting binaural perception and sound source segregation., Design: A binaurally-linked model-based fast-acting dynamic compression algorithm designed to approximate the normal-hearing basilar membrane (BM) input-output function in hearing-impaired listeners is suggested. A multi-center evaluation in comparison with an alternative binaural and two bilateral fittings was performed to assess the effect of binaural synchronisation on (a) speech intelligibility and (b) perceived quality in realistic conditions., Study Sample: 30 and 12 hearing impaired (HI) listeners were aided individually with the algorithms for both experimental parts, respectively., Results: A small preference towards the proposed model-based algorithm in the direct quality comparison was found. However, no benefit of binaural-synchronisation regarding speech intelligibility was found, suggesting a dominant role of the better ear in all experimental conditions., Conclusion: The suggested binaural synchronisation of compression algorithms showed a limited effect on the tested outcome measures, however, linking could be situationally beneficial to preserve a natural binaural perception of the acoustical environment.

A review about technical and perceptual factors in hearing aid technology, research and development is provided, covering current commercial solutions, underlying models of hearing loss for usage in hearing devices and emerging future technical solutions for hearing aid functionalities. A chain of techniques has provided incremental, but steady increases in user benefit, e.g. in the fields of hearing aid amplification, feedback suppression, dynamic compression, noise reduction and situation adaptation. The models describing the perceptual consequences of sensorineural hearing impairment describe the effects on the acoustical level, the neurosensory level and the cognitive level and provide the framework for compensatory (or even substitutional) functions of hearing aids in terms of the attenuation component, the distortion component and the neural component of the hearing loss. A major factor is the requirement of a strong individualisation of hearing aid solutions calling for an appropriate assessment of the different sensorineural components of a hearing loss, especially with respect to bilateral and binaural hearing aid solutions.

Objective: Single-channel noise reduction (SCNR) and dynamic range compression (DRC) are important elements in hearing aids. Only relatively few studies have addressed interaction effects and typically used real hearing aids with limited knowledge about the integrated algorithms. Here the potential benefit of different combinations and integration of SCNR and DRC was systematically assessed., Design: Ten different systems combining SCNR and DRC were implemented, including five serial arrangements, a parallel and two multiplicative approaches. In an instrumental evaluation, signal-to-noise ratio (SNR) improvement and spectral contrast enhancement (SCE) were assessed. Quality ratings at 0 and +6 dB SNR, and speech reception thresholds (SRTs) in noise were measured using stationary and babble noise., Study Sample: Thirteen young normal-hearing (NH) listeners and 12 hearing-impaired (HI) listeners participated., Results: In line with an increased segmental SNR and spectral contrast compared to a serial concatenation, the parallel approach significantly reduced the perceived noise annoyance for both subject groups. The proposed multiplicative approaches could partly counteract increased speech distortions introduced by DRC and achieved the best overall quality for the HI listeners., Conclusions: For high SNRs well above the individual SRT, the specific combination of SCNR and DRC is perceptually relevant and the integrative approaches were preferred.

Objective: To investigate the influence of an algorithm designed to enhance or magnify interaural difference cues on speech signals in noisy, spatially complex conditions using both technical and perceptual measurements. To also investigate the combination of interaural magnification (IM), monaural microphone directionality (DIR), and binaural coherence-based noise reduction (BC)., Design: Speech-in-noise stimuli were generated using virtual acoustics. A computational model of binaural hearing was used to analyse the spatial effects of IM. Predicted speech quality changes and signal-to-noise-ratio (SNR) improvements were also considered. Additionally, a listening test was carried out to assess speech intelligibility and quality., Study Sample: Listeners aged 65-79 years with and without sensorineural hearing loss (N = 10 each)., Results: IM increased the horizontal separation of concurrent directional sound sources without introducing any major artefacts. In situations with diffuse noise, however, the interaural difference cues were distorted. Preprocessing the binaural input signals with DIR reduced distortion. IM influenced neither speech intelligibility nor speech quality., Conclusions: The IM algorithm tested here failed to improve speech perception in noise, probably because of the dispersion and inconsistent magnification of interaural difference cues in complex environments.

Objectives: Previous studies show that intracochlear electrical stimulation independent of environmental sounds appears to suppress tinnitus, even long-term. In order to assess the viability of this potential treatment option it is essential to study the effects of this tinnitus specific electrical stimulation on speech perception., Design: A randomised, prospective crossover design., Study Sample: Ten patients with unilateral or asymmetric hearing loss and severe tinnitus complaints., Results: The audiological effects of standard clinical CI, formal auditory training and tinnitus specific electrical stimulation were investigated. Results show that standard clinical CI in unilateral or asymmetric hearing loss is shown to be beneficial for speech perception in quiet, speech perception in noise and subjective hearing ability. Formal auditory training does not appear to improve speech perception performance. However, CI-related discomfort reduces significantly more rapidly during CI rehabilitation in subjects receiving formal auditory training. Furthermore, tinnitus specific electrical stimulation has neither positive nor negative effects on speech perception., Conclusions: In combination with the findings from previous studies on tinnitus suppression using intracochlear electrical stimulation independent of environmental sounds, the results of this study contribute to the viability of cochlear implantation based on tinnitus complaints.

Objective: Research findings concerning the relation between benefit from hearing aid (HA) noise suppression and working memory function are inconsistent. The current study thus investigated the effects of three noise suppression algorithms on auditory working memory and the relation with reading span., Design: Using a computer simulation of bilaterally fitted HAs, four settings were tested: (1) unprocessed, (2) directional microphones, (3) single-channel noise reduction, and (4) binaural coherence-based noise reduction. Settings 2-4 were matched in terms of the speech-weighted signal-to-noise ratio (SNR) improvement. Auditory working memory was assessed at +6 dB SNR using listening span and N-back paradigms., Study Sample: Twenty experienced HA users aged 55-80 years with large differences in reading span., Results: For the listening span measurements, there was an influence of HA setting on sentence-final word recognition and recall, with the directional microphones leading to ∼6% better performance than the single-channel noise reduction. For the N-back measurements, there was substantial test-retest variability and no influence of HA setting. No interactions with reading span were found., Conclusion: HA noise suppression may affect the recognition and recall of speech at positive SNRs, irrespective of individual reading span. Future work should improve the reliability of the auditory working memory measurements.

Objective: To compare preference for and performance of manually selected programmes to an automatic sound classifier, the Phonak AutoSense OS., Design: A single blind repeated measures study. Participants were fit with Phonak Virto V90 ITE aids; preferences for different listening programmes were compared across four different sound scenarios (speech in: quiet, noise, loud noise and a car). Following a 4-week trial preferences were reassessed and the users preferred programme was compared to the automatic classifier for sound quality and hearing in noise (HINT test) using a 12 loudspeaker array., Study Sample: Twenty-five participants with symmetrical moderate-severe sensorineural hearing loss., Results: Participant preferences of manual programme for scenarios varied considerably between and within sessions. A HINT Speech Reception Threshold (SRT) advantage was observed for the automatic classifier over participant's manual selection for speech in quiet, loud noise and car noise. Sound quality ratings were similar for both manual and automatic selections., Conclusions: The use of a sound classifier is a viable alternative to manual programme selection.

Objective: The National Acoustic Laboratories Dynamic Conversations Test (NAL-DCT) is a new test of speech comprehension that incorporates a realistic environment and dynamic speech materials that capture certain features of everyday conversations. The goal of this study was to assess the suitability of the test for studying the consequences of hearing loss and amplification in older listeners., Design: Unaided and aided comprehension scores were measured for single-, two- and three-talker passages, along with unaided and aided sentence recall. To characterise the relevant cognitive abilities of the group, measures of short-term working memory, verbal information-processing speed and reading comprehension speed were collected., Study Sample: Participants were 41 older listeners with varying degrees of hearing loss., Results: Performance on both the NAL-DCT and the sentence test was strongly driven by hearing loss, but performance on the NAL-DCT was additionally related to a composite cognitive deficit score. Benefits of amplification were measurable but influenced by individual test SNRs., Conclusions: The NAL-DCT is sensitive to the same factors as a traditional sentence recall test, but in addition is sensitive to the cognitive factors required for speech processing. The test shows promise as a tool for research concerned with real-world listening.

Objective: The purpose of this study was to evaluate the effects of directional microphone use on laboratory measures of sentence recognition, listening effort and localisation. An additional purpose of this study was to evaluate the effects of asymmetric directional microphone use on the same laboratory measures., Design: Three hearing aid conditions were evaluated: (1) bilateral omnidirectional microphones, (2) bilateral directional microphones and (3) asymmetric microphones (directional microphone for only one hearing aid). Sentence recognition performance was evaluated using a connected speech test. Listening effort was evaluated using a dual-task paradigm with a response time-based secondary task requiring word categorisation. Localisation was examined using a complex task requiring localisation and recall of speech originating from one of four loudspeakers in the horizontal plane (-60°, -45°, +45°, +60°)., Study Sample: Eighteen adults (M = 61.8 years) with symmetrical, moderate-to-severe hearing loss participated., Results: Performance on each task was analysed separately using a repeated measures analysis of variance. Results revealed directional benefits for sentence recognition and listening effort, but microphone setting did not affect localisation. Performance was equivalent with symmetric and asymmetric directional configurations., Conclusions: Bilateral and asymmetric directional microphone configurations equally improved sentence recognition and listening effort; neither affected localisation or recall.

Objective: The objective was to assess the degradation of speech sound quality produced by frequency compression for listeners with extensive high-frequency dead regions (DRs)., Design: Quality ratings were obtained using values of the starting frequency (Sf) of the frequency compression both below and above the estimated edge frequency, f e , of each DR. Thus, the value of Sf often fell below the lowest value currently used in clinical practice. Several compression ratios were used for each value of Sf. Stimuli were sentences processed via a prototype hearing aid based on Phonak Exélia Art P., Study Sample: Five participants (eight ears) with extensive high-frequency DRs were tested., Results: Reductions of sound-quality produced by frequency compression were small to moderate. Ratings decreased significantly with decreasing Sf and increasing CR. The mean ratings were lowest for the lowest Sf and highest CR. Ratings varied across participants, with one participant rating frequency compression lower than no frequency compression even when Sf was above f e ., Conclusions: Frequency compression degraded sound quality somewhat for this small group of participants with extensive high-frequency DRs. The degradation was greater for lower values of Sf relative to f e , and for greater values of CR. Results varied across participants.

Objective: This study investigated outcomes and predictive factors, specifically language skills, for a group of prelingually hearing-impaired adults who received a cochlear implant., Design: Speech perception data, demographic information, and other related variables such as communication mode, residual hearing, and receptive language abilities were explored. Pre- and post-implant speech perception scores were compared and multiple regression analysis was used to identify significant predictive relationships., Study Sample: The study included 43 adults with a prelingual onset of hearing loss, who proceeded with cochlear implantation at the Royal Victorian Eye and Ear Hospital in Melbourne, Australia., Results: The majority of patients experienced benefit from their cochlear implants, with 88% demonstrating significant improvement in speech perception performance. Volunteers achieved better post-operative speech perception scores if they had a shorter duration of severe-to-profound hearing loss, better language skills, and used an exclusively oral communication mode., Conclusions: Although post-operative speech perception performance is significantly poorer for prelingually hearing-impaired adults compared to postlingually hearing-impaired patients, the study group demonstrated significant benefit from their cochlear implants. The variability in post-operative outcomes can be predicted to some extent from the hearing history and language abilities of the individual patient.

Objective: This paper aimed to estimate the difference in speech perception outcomes that may occur due to timing of cochlear implantation in relation to the progression of hearing loss., Design: Data from a large population-based sample of adults with acquired hearing loss using cochlear implants (CIs) was used to estimate the effects of duration of hearing loss, age, and pre-implant auditory skills on outcomes for a hypothetical standard patient., Study Sample: A total of 310 adults with acquired severe/profound bilateral hearing loss who received a CI in Melbourne, Australia between 1994 and 2006 provided the speech perception data and demographic information to derive regression equations for estimating CI outcomes., Results: For a hypothetical CI candidate with progressive sensorineural hearing loss, the estimates of speech perception scores following cochlear implantation are significantly better if implantation occurs relatively soon after onset of severe hearing loss and before the loss of all functional auditory skills., Conclusions: Improved CI outcomes and quality of life benefit may be achieved for adults with progressive severe hearing loss if they are implanted earlier in the progression of the pathology.

Objective: To use a computer model of impaired hearing to explore the effects of a physiologically-inspired hearing-aid algorithm on a range of psychoacoustic measures., Design: A computer model of a hypothetical impaired listener's hearing was constructed by adjusting parameters of a computer model of normal hearing. Absolute thresholds, estimates of compression, and frequency selectivity (summarized to a hearing profile) were assessed using this model with and without pre-processing the stimuli by a hearing-aid algorithm. The influence of different settings of the algorithm on the impaired profile was investigated. To validate the model predictions, the effect of the algorithm on hearing profiles of human impaired listeners was measured., Study Sample: A computer model simulating impaired hearing (total absence of basilar membrane compression) was used, and three hearing-impaired listeners participated., Results: The hearing profiles of the model and the listeners showed substantial changes when the test stimuli were pre-processed by the hearing-aid algorithm. These changes consisted of lower absolute thresholds, steeper temporal masking curves, and sharper psychophysical tuning curves., Conclusion: The hearing-aid algorithm affected the impaired hearing profile of the model to approximate a normal hearing profile. Qualitatively similar results were found with the impaired listeners' hearing profiles.

Objective: Establish up-to-date evidence-based guidelines for recommending cochlear implantation for young children., Design: Speech perception results for early-implanted children were compared to children using traditional amplification. Equivalent pure-tone average (PTA) hearing loss for cochlear implant (CI) users was established. Language of early-implanted children was assessed over six years and compared to hearing peers., Study Sample: Seventy-eight children using CIs and 62 children using traditional amplification with hearing losses ranging 25-120 dB HL PTA (speech perception study). Thirty-two children who received a CI before 2.5 years of age (language study)., Results: Speech perception outcomes suggested that children with a PTA greater than 60 dB HL have a 75% chance of benefit over traditional amplification. More conservative criteria applied to the data suggested that children with PTA greater than 82 dB HL have a 95% chance of benefit. Children implanted under 2.5 years with no significant cognitive deficits made normal language progress but retained a delay approximately equal to their age at implantation., Conclusions: Hearing-impaired children under three years of age may benefit from cochlear implantation if their PTA exceeds 60 dB HL bilaterally. Implantation as young as possible should minimize any language delay resulting from an initial period of auditory deprivation.

Objective: The overall goal of this work is to create new speech perception tests that more closely resemble real world communication and offer an alternative or complement to the commonly used sentence recall test., Design: We describe the development of a new ongoing speech comprehension test based on short everyday passages and on-the-go questions. We also describe the results of an experiment conducted to compare the psychometric properties of this test to those of a sentence test., Study Sample: Both tests were completed by a group of listeners that included normal hearers as well as hearing-impaired listeners who participated with and without their hearing aids., Results: Overall, the psychometric properties of the two tests were similar, and thresholds were significantly correlated. However, there was some evidence of age/cognitive effects in the comprehension test that were not revealed by the sentence test., Conclusions: This new comprehension test promises to be useful for the larger goal of creating laboratory tests that combine realistic acoustic environments with realistic communication tasks. Further efforts will be required to assess whether the test can ultimately improve predictions of real-world outcomes.

Objective: The individual outcome after cochlear implantation in children with auditory synaptopathy/neuropathy (AS/AN) is difficult to predict. A tool for preoperative assessment would be helpful for counseling parents. This study evaluates the outcome after CI in children with AS/AN and with sensorineural hearing loss (SNHL), and correlates it with the preoperative ECochG results in order to find specific parameters of prognostic value., Design: The improvement of auditory behavior after CI was retrospectively assessed using the LittlEARS questionnaire and quantified in a score (LS). This score was correlated with the CAP/SP ratio in the preoperative ECochG. The score was further correlated with the patient's age six months following CI., Study Sample: Nine children with AS/AN were compared to nine children with SNHL., Results: Both groups showed a significant improvement in LS following CI. There was a significant positive correlation between the CAP/SP ratio and the improvement in LS in all children. The correlation between age and LS was significantly negative in the SNHL group and positive in the AS/AN group., Conclusion: All children with AS/AN and SNHL benefit to a similar extent from CI. The preoperatively assessed CAP/SP ratio has a prognostic value for the development of auditory behavior following CI.

Objective: While potentially improving audibility for listeners with considerable high frequency hearing loss, the effects of implementing nonlinear frequency compression (NFC) for listeners with moderate high frequency hearing loss are unclear. The purpose of this study was to investigate the effects of activating NFC for listeners who are not traditionally considered candidates for this technology., Design: Participants wore study hearing aids with NFC activated for a 3-4 week trial period. After the trial period, they were tested with NFC and with conventional processing on measures of consonant discrimination threshold in quiet, consonant recognition in quiet, sentence recognition in noise, and acceptableness of sound quality of speech and music., Study Sample: Seventeen adult listeners with symmetrical, mild to moderate sensorineural hearing loss participated. Better ear, high frequency pure-tone averages (4, 6, and 8 kHz) were 60 dB HL or better., Results: Activating NFC resulted in lower (better) thresholds for discrimination of /s/, whose spectral center was 9 kHz. There were no other significant effects of NFC compared to conventional processing., Conclusion: These data suggest that the benefits, and detriments, of activating NFC may be limited for this population.

Objective: The objective of this study is to describe the technical design and verify the technical performance of a new bone conduction implant (BCI) system., Design: The BCI consists of an external audio processor and an implanted unit called the bridging bone conductor. These two units use an inductive link to communicate with each other through the intact skin in order to drive an implanted transducer., Study Sample: In this study, the design of the full BCI system has been described and verified on a skull simulator and on real patients., Results: It was found that the maximum output force (peak 107 dB re 1 μN) of the BCI is robust for skin thickness range of 2-8 mm and that the total harmonic distortion is below 8% in the speech frequency range for 70 dB input sound pressure level. The current consumption is 7.5 mA, which corresponds to 5-7 days use with a single battery., Conclusions: This study shows that the BCI is a robust design that gives a sufficiently high output and an excellent sound quality for the hearing rehabilitation of indicated patients.

Objective: The aim was to investigate whether frequency compression (FC) hearing aids provide additional benefit to that conferred by conventional amplification., Design: Participants wore the same hearing aid with FC enabled and disabled for six weeks (ABA design) in each condition. Speech recognition tests (in both quiet and in noise) were administered alongside two questionnaires. Performance was compared across the two signal processing conditions and at different time points., Study Sample: Twelve experienced hearing-aid users (aged 65-84 years old) with moderate-to-severe high-frequency hearing loss participated in the study., Results: FC resulted in statistically significantly higher mean scores in all of the administered speech tests. Improvements over time were limited to high frequency phoneme perception. No effect of FC on self-report outcomes was observed., Conclusions: FC may lead to significant improvements in speech perception outcomes in both quiet and noise for many individuals. No participant was significantly disadvantaged by the use of FC.

Objective: Binaural beamformers are super-directional hearing aids created by combining microphone outputs from each side of the head. While they offer substantial improvements in SNR over conventional directional hearing aids, the benefits (and possible limitations) of these devices in realistic, complex listening situations have not yet been fully explored. In this study we evaluated the performance of two experimental binaural beamformers., Design: Testing was carried out using a horizontal loudspeaker array. Background noise was created using recorded conversations. Performance measures included speech intelligibility, localization in noise, acceptable noise level, subjective ratings, and a novel dynamic speech intelligibility measure., Study Sample: Participants were 27 listeners with bilateral hearing loss, fitted with BTE prototypes that could be switched between conventional directional or binaural beamformer microphone modes., Results: Relative to the conventional directional microphones, both binaural beamformer modes were generally superior for tasks involving fixed frontal targets, but not always for situations involving dynamic target locations., Conclusions: Binaural beamformers show promise for enhancing listening in complex situations when the location of the source of interest is predictable.

Objectives: To investigate the preservation of residual hearing in subjects who received the Nucleus Hybrid L24 cochlear implant. To investigate the performance benefits up to one year post-implantation in terms of speech recognition, sound quality, and quality of life., Design: Prospective, with sequential enrolment and within-subject comparisons. Post-operative performance using a Freedom Hybrid sound processor was compared with that of pre-operative hearing aids., Study Sample: Sixty-six adult hearing-impaired subjects with bilateral severe-to-profound high frequency hearing loss., Results: Group median increase in air-conduction thresholds in the implanted ear for test frequencies 125-1000 Hz was < 15 dB across the population; both immediately and one year post-operatively. Eighty-eight percent of subjects used the Hybrid processor at one year post-op. Sixty-five percent of subjects had significant gain in speech recognition in quiet, and 73% in noise (≥ 20 percentage points/2 dB SNR). Mean SSQ subscale scores were significantly improved (+ 1.2, + 1.3, + 1.8 points, p < 0.001), as was mean HUI3 score (+ 0.117, p < 0.01). Combining residual hearing with CI gave 22-26 %age points mean benefit in speech recognition scores over CI alone (p < 0.01)., Conclusions: Useful residual hearing was conserved in 88% of subjects. Speech perception was significantly improved over preoperative hearing aids, as was sound quality and quality of life.

Objective: Backward-facing directional processing (Back-DIR) is an algorithm that employs an anti-cardioid directivity pattern to enhance speech arriving from behind the listener. An experiment that was originally designed to evaluate Back-DIR, together with its follow-up experiment, are reported to illustrate how hearing-aid users' voices could affect directional benefit., Design: Speech recognition performance was measured in a speech-180°/noise-0° configuration, with aids programmed to Back-DIR enabled or omnidirectional processing. In the original experiment, the conventional hearing-in-noise test (HINT) was used, wherein listeners repeated heard sentences. In the follow-up experiment, a modified HINT was used, wherein a carrier phrase was presented before each sentence., Study Sample: Fifteen adults with sensorineural hearing loss participated in both experiments., Results: Significant Back-DIR benefit (relative to omnidirectional processing) was observed in the follow-up experiment, while not in the original experiment., Conclusions: In the original experiment, hearing aids were affected by listeners' voices such that Back-DIR was not always activated when the target speech was presented. In the follow-up experiment, listeners' voice effects were eliminated by the carrier phrase activating Back-DIR before the sentences were presented. The results suggest that the effect of hearing-aid technologies is highly dependent on the characteristics of listening conditions.

Objective: Evaluation of the effectiveness of imaging and genetic testing, and establishment of a cost-effective diagnostic protocol for the etiologic diagnosis of sensorineural hearing loss (SNHL) in Brazil., Design: Prospective cohort study., Study Sample: Analysis of 100 unrelated Brazilian patients with severe to profound bilateral SNHL submitted to cochlear implant (CI) between 2002 and 2010 at the University of Campinas hospital. The study was based upon three groups: individuals with congenital, progressive, and sudden SNHL., Results: After the diagnostic investigation, the number of cases with unknown etiology was reduced from 72 to 42 (a 42% reduction); 25% of cases were due to environmental factors, 19% to genetic causes, and 14% to inner-ear abnormalities or other clinical features. The genetic and imaging findings contributed to the diagnosis of SNHL in 19% and 20% of the cases analysed, respectively. Molecular testing mainly contributed to the diagnosis of patients with congenital SNHL, while the contribution of radiologic examination was higher for individuals with progressive or sudden SNHL. A sequential diagnostic protocol was proposed based on these data., Conclusions: The proposed diagnostic workup algorithm could provide better optimization of etiologic diagnosis, as well as reduced costs, compared to a simultaneous testing approach.

Objective: Tinnitus is a perceived sound that cannot be attributed to an external source. This study attempts to identify a prescription of amplification that is optimized as a first-fit setting for tinnitus relief., Design: Participants compared the effect of high frequency amplification on their tinnitus. Stimuli were 13 speech files with different amounts of high frequency amplification (three cut-off frequencies and four gain settings) to simulate the effects of a change in DSL(I/O) v5.0 prescription in the high frequencies., Study Sample: Twenty-five participants with chronic tinnitus participated in the study., Results: A 6-dB reduction to prescribed gain at 2 kHz emerged as the most preferred output (26.47% participants) to interfere with participants' tinnitus. Overall, 70.58% of the participants' preferred a 3 to 6 dB reduction in output while 29.42% preferred a similar increase across all cut-off frequencies. A trend was observed in which the higher the tinnitus pitch the more similar the preferred output to DSL(I/O) v5.0., Conclusion: DSL(I/O) v5.0 appears to be a good starting point for prescription of hearing-aid output for tinnitus management. Long-term benefits of different prescriptions for tinnitus still need to be ascertained.

Objective: Satisfaction with amplification in daily life (SADL) may quantify satisfaction with hearing aids. We translated and validated a Chinese version of SADL (CSADL)., Design: The SADL was translated from English to Mandarin Chinese by two bilingual physicians. The CSADL was administered to hearing-aid users and tested for reliability and validity., Study Sample: There were 155 hearing-aid users who completed the CSADL prospectively, and 39 subjects were retested after 4 to 6 weeks for test-retest reliability., Results: The CSADL had good internal consistency (Cronbach α = 0.63 to 0.92), within survey reliability (r = 0.54 to 0.69; P ≤ .05), and test-retest reliability (r = 0.93 to 0.98; P ≤ .05). The CSADL dimensions correlated well with worse-ear speech discrimination score (P ≤ .05). The CSADL global score significantly correlated with the general health (r = 0.236; P ≤ .05), vitality (r = 0.162; P ≤ .05), social functioning (r = 0.190; P ≤ .05), and mental health (r = 0.224; P ≤ .05) subscales of the Mandarin Chinese Taiwan version of the medical outcome 36-item short-form health survey., Conclusions: The CSADL is a valid and reliable questionnaire to evaluate satisfaction among Chinese hearing-aid users.

Objectives: It has been shown that noise reduction algorithms can reduce the negative effects of noise on memory processing in persons with normal hearing. The objective of the present study was to investigate whether a similar effect can be obtained for persons with hearing impairment and whether such an effect is dependent on individual differences in working memory capacity., Design: A sentence-final word identification and recall (SWIR) test was conducted in two noise backgrounds with and without noise reduction as well as in quiet. Working memory capacity was measured using a reading span (RS) test., Study Sample: Twenty-six experienced hearing-aid users with moderate to moderately severe sensorineural hearing loss., Results: Noise impaired recall performance. Competing speech disrupted memory performance more than speech-shaped noise. For late list items the disruptive effect of the competing speech background was virtually cancelled out by noise reduction for persons with high working memory capacity., Conclusions: Noise reduction can reduce the adverse effect of noise on memory for speech for persons with good working memory capacity. We argue that the mechanism behind this is faster word identification that enhances encoding into working memory.

Objective: A recent study suggested that placebo effects are a source of bias in non-blinded hearing-aid trials. Given the potential impact of this finding on the interpretation of non-blinded trials and design of future research trials, the objective of the present study was to investigate the reliability of this effect., Design: Using the same procedure as an earlier study, participants were told that they were taking part in a trial of new hearing-aid technology. Participants compared two devices that were acoustically identical, except one was described as "new" and the other as "conventional". Participants completed a speech-in-noise test, sound quality ratings, and rated overall personal preference for both hearing aids., Study Sample: Sixteen adult hearing-aid users., Results: Participants had significantly better mean speech-in-noise performance (70.9% versus 66.8%, Z = 2.30, p = 0.02, effect size Pearson's r = 0.15) and sound quality ratings for the "new" hearing aid (8.1 versus 7.4, Z = - 2.99, p = 0.003, r = 0.28). A significant proportion of participants (75%) expressed an overall preference for the "new" hearing aid (p = 0.001, effect size φc = 0.66)., Conclusion: Placebo effects reliably impact on hearing-aid trials. In order to control for placebo effects, double-blind methodology is optimal. However, when double-blinding is not possible other strategies may be appropriate.