Search

Contains fulltext : 219908.pdf (Publisher’s version ) (Closed access) Objective: Bimodal listeners vary in the amount of benefit they receive from wearing the contralateral hearing aid. This may partially depend on the listener's auditory processing capacities. The current study explores whether the P300 event-related potential can provide insight into the mechanisms underlying the benefits of wearing a contralateral hearing aid.Design: P300s were recorded using an oddball paradigm with 500 and 250 Hz tone-bursts as standard and deviant stimuli, respectively. Subjects counted the number of deviants - a measure of performance. N2b latencies, P300 latencies, N2b-P300 amplitudes, and performance were assessed during CI-only and bimodal listening.Study sample: Five bimodal listeners.Results: P300s were present in four subjects. Amplitudes were larger during bimodal listening (bimodal: 22.3 +/- 4.83 microV, CI-only: 13.1 +/- 3.86 microV). Both N2b and P300 latencies were shorter during bimodal (N2b: 265 +/- 20.0 ms, P300: 551 +/- 129.4 ms) than CI-only listening (N2b: 326 +/- 42.2 ms, P300: 402 +/- 38.4 ms). While performance often reached ceiling level, the difference between the standard and deviant was generally more salient during bimodal listening.Conclusions: This study provides a proof-of-concept, suggesting that P300s may provide insight into benefits that are not always measurable with behavioural tasks.

The aims of this study were to collect data on electrically evoked compound action potential (eCAP) and electrically evoked stapedius reflex thresholds (eSRT) in HiResolution(TM) cochlear implant (CI) users, and to explore the relationships between these objective measures and behavioural measures of comfort levels (M-levels).A prospective study on newly implanted subjects was designed. The eCAP was measured intra-operatively and at first fitting through neural response imaging (NRI), using the SoundWave(TM) fitting software. The eSRT was measured intra-operatively by visual monitoring of the stapes, using both single-electrode stimulation and speech bursts (four electrodes stimulated at the same time). Measures of M-levels were performed according to standard clinical practice and collected at first fitting, 3 and 6 months of CI use.One hundred seventeen subjects from 14 centres, all implanted unilaterally with a HiResolution CII Bionic Ear(®) or HiRes 90K(®), were included in the study. Speech burst stimulation elicited a significantly higher eSRT success rate than single-electrode stimulation, 84 vs. 64% respectively. The NRI success rate was 81% intra-operatively, significantly increasing to 96% after 6 months. Fitting guidelines were defined on the basis of a single NRI measurement. Correlations, analysis of variance, and multiple regression analysis were applied to generate a predictive model for the M-levels.Useful insights were produced into the behaviour of objective measures according to time, electrode location, and fitting parameters. They may usefully assist in programming the CI when no reliable feedback is obtained through standard behavioural procedures.

Objective The purpose of this study was to evaluate the reliability of the vestibular evoked myogenic potential (VEMP) response in a clinical setting when only a feedback mechanism is available for monitoring background EMG. Methods Sixty-one healthy subjects participated in the investigation of the within-session reliability, whereas fourteen of them were retested after one week for examination of the between-session reliability. VEMPs were recorded using 500Hz tone bursts with the subjects in a sitting position and their heads turned away from the test ear to the contralateral shoulder, thereby pushing their chin against the inflatable cuff of a blood pressure manometer, serving as feedback method. Results The feedback method revealed latency and amplitude values comparable to other data in the literature where different test conditions were applied. Excellent reliability with ICC values ranging from 0.78 to 0.96 and CV ME values ranging from 4% to 36%, was achieved for P1 and N1 latency, threshold and interpeak amplitude. Good reliability with ICC values of 0.65 and 0.68 and CV ME values of 170% and 189%, was obtained for the asymmetry ratio. Conclusions A unilateral muscle contraction controlled by a feedback mechanism resulted in reliable response parameters, comparable right to left and corresponding to literature data obtained in different test conditions. Significance The use of a blood pressure manometer as feedback mechanism combined with a meticulously controlled positioning of the head and contraction of the SCM muscle provides a reliable alternative in clinical settings, when the background muscle contraction cannot be measured or software related correction algorithms are not accessible.

Item does not contain fulltext OBJECTIVES: Age-related hearing loss hampers the ability to understand speech in adverse listening conditions. This is attributed to a complex interaction of changes in the peripheral and central auditory system. One aspect that may deteriorate across the lifespan is binaural interaction. The present study investigates binaural interaction at the level of the auditory brainstem. It is hypothesized that brainstem binaural interaction deteriorates with advancing age. DESIGN: Forty-two subjects of various age participated in the study. Auditory brainstem responses (ABRs) were recorded using clicks and 500 Hz tone-bursts. ABRs were elicited by monaural right, monaural left, and binaural stimulation. Binaural interaction was investigated in two ways. First, grand averages of the binaural interaction component were computed for each age group. Second, wave V characteristics of the binaural ABR were compared with those of the summed left and right ABRs. RESULTS: Binaural interaction in the click ABR was demonstrated by shorter latencies and smaller amplitudes in the binaural compared with the summed monaural responses. For 500 Hz tone-burst ABR, no latency differences were found. However, amplitudes were significantly smaller in the binaural than summed monaural condition. An age-effect was found for 500 Hz tone-burst, but not for click ABR. CONCLUSIONS: Brainstem binaural interaction seems to decline with age. Interestingly, these changes seem to be stimulus-dependent.

The aim of the present study was to construct and compare two caloric test protocols, one for water irrigation, and one for air insufflation. A set of reference data was constructed and tabulated as well as the intersubject variability. The effect of age, sex, ear, and temperature, as well as a possible priming effect and order effect were investigated. Forty-seven subjects (18-58 years) without otological or vestibular history participated. Four response parameters were investigated: slow component velocity (SCV), frequency, unilateral weakness (UW), and directional preponderance (DP). Statistically higher SCV values were obtained for water compared to air, with statistically higher standard deviations for SCV water values. No influences of age, sex, ear, or temperature could be demonstrated on any of the response parameters. The same applied for the presence of an order effect and a priming effect. Comparing the two protocols to one another led the present authors to favour water as the standard irrigation medium, and air only in situations where water is contra-indicated.

The present study utilized a commercially available multiple auditory steady-state response (ASSR) system to test normal hearing adults (n=55). The primary objective was to evaluate the impact of the mixed modulation (MM) and the novel proposed exponential AM(2)/FM stimuli on the signal-to-noise ratio (SNR) and threshold estimation accuracy, through a within-subject comparison. The second aim was to establish a normative database for both stimulus types. The results demonstrated that the AM(2)/FM and MM stimulus had a similar effect on the SNR, whereas the ASSR threshold results revealed that the AM(2)/FM produced better thresholds than the MM stimulus for the 500, 1000, and 4000 Hz carrier frequency. The mean difference scores to tones of 500, 1000, 2000, and 4000 Hz were for the MM stimulus: 20+/-12, 14+/-9, 10+/-8, and 12+/-8 dB; and for the AM(2)/FM stimulus: 18+/-13, 12+/-8, 11+/-8, and 10+/-8 dB, respectively. The current research confirms that the AM(2)/FM stimulus can be used efficiently to test normal hearing adults.

In order to develop a sensitive audiometric protocol for identifying ototoxicity in children, a retrospective study of 16 children treated with cisplatin and/or carboplatin was performed. Audiometric testing was done by means of pure-tone threshold audiometry (PTA), high-frequency audiometry (HFA), and distortion product otoacoustic emissions (DPOAEs).Cisplatin caused a sensorineural high-frequency hearing loss in the study group compared to the controls (p

The purpose of this study was to determine and to compare the overall intelligibility, articulation, resonance, and voice characteristics in children using cochlear implants (CI) and children using conventional hearing aids (HA). Nine prelingually deaf children using CI and six children with a prelingual severe hearing loss using HA, were selected to participate. Objective (DSI, nasalance scores) as well as subjective assessment techniques (perceptual evaluations) were used. Both the CI and HA children demonstrated normal vocal quality and resonance but showed the presence of articulation disorders. In the CI children, intelligibility was significantly better compared to the HA children. Significantly more phonetic and phonological disorders were present in the HA children. The results of this study show a poorer intelligibility of the HA children in comparison with the CI children which is probably due to the occurrence of significantly more phonetic and phonological disorders. Future detailed analysis i...

In this study 22 patients (44 ears) with noise-induced permanent hearing loss were audiologically evaluated using transient-evoked otoacoustic emissions (TEOAE) and auditory brain-stem response (ABR). Twenty-one normal subjects (42 ears) without exposure to occupational noise were used as controls. Based upon the hearing loss at 4, 3, 2 and 1 kHz on the pure-tone audiogram, they were classified into four groups. In group 1 (eight ears), emissions were present in all ears but their TEOAE-noise level and their reproducibility (percentage) proved to be weak. The auditory brain-stem response (ABR) indicated that the I/V amplitude ratio, the latency values of wave V and the I–V intervals fell within the normal range in all ears. In Group 2 (14 ears), 40 per cent had no emissions, whereas the remaining ears showed weak emissions. The ABR revealed that in all ears the I/V amplitude ratio became small while wave V peak latency as well as I–V intervals were within the normal range. In Group 3 (10 ears), emissions were absent in 50 per cent, while in the other ears the emissions were very weak. The ABR revealed that the I/V amplitude ratio, which could be calculated in the 60 per cent in which wave I was present, was smaller than in Group 2. Wave V latency as well as I–V intervals were within the normal range. In Group 4 (12 ears), none of the ears showed emissions. The ABR indicated that the I/V amplitude ratio was much smaller when wave I was present (27 per cent) as well as I–V interval values being within the normal range. Wave V absolute latency value (δV index) indicated a positive index in 17 per cent of this group (two ears) when wave I was absent. In the present study a dynamic process from cochlear outer hair cells to cochlear neurons was seen, correlating with an increasing hearing loss.

In cases of substantial auditory handicap, the degree of pure-tone hearing loss or hearing loss for speech is seen as the primary determining factor. Sometimes the presence of tinnitus complaints and disproportionate masking effects of noise on speech reception are seen as aggravating factors. To investigate the relevance of tinnitus and masking effects in the context of hearing disability, four factorial designs with self-perceived hearing disability as the dependent variable were submitted to an analysis of variance. Impact of masking and tinnitus complaints were treated as independent variables with two levels and were each combined with a second independent variable to form a 2 x 2 fixed factor statistical model. This second independent variable was either hearing loss for pure tones (first and second model) or speech reception ability (third and fourth model). Both hearing loss for pure tones and speech reception capability were found to be significant explanatory factors for hearing disability. Impact of masking, if juxtaposed to average pure-tone hearing loss (first model), also came out of the analysis as a significant factor in hearing disability, whereas the tinnitus factor did not reach significance levels. No significant interactions between factors were found. The results support the idea of the differentiating audiogram-based disability estimates by taking noise susceptibility into account. The findings also suggest in an equivocal relation of tinnitus with hearing disability, which prevents it from being a straightforward disability predictor.

The effects of stimulus rise-fall and plateau times on the middle-latency response (MLR) waveform (Na-Pa amplitude and Pa latency) were investigated in 14 normally hearing subjects and an objective MLR threshold was evaluated at low and middle frequencies in ten normally hearing subjects and ten patients with slope of sensorineural hearing loss, using a selected stimulus-envelope time. After analyzing the effects of envelope times on the MLR waveform and the spectra of tone-pips, it was found that a rise-fall time of 4 ms with a plateau of 2 ms (4–2–4) is an acceptable compromise between a synchronous discharge and frequency specificity for estimating the MLR threshold. The MLR threshold produced by 4–2–4 tone-pips approximated the psychoacoustic threshold at low and middle frequencies in the normal and hearing impaired subjects. This demonstrates the clinical usefulness of the MLR in estimating low- and middle-frequency thresholds.

Hearing disability can be measured by questionnaires, interviews or self-ratings. As these measurement techniques are not always appropriate for direct application in individual cases, particularly in the context of compensation claims, the assessment is sometimes reduced to a surrogate measure derived from audiometric thresholds. No final agreement emerges from correlation studies on hearing disability as to the optimal set of audiometric descriptors. However, a multiple regression equation, describing the relationship between audiometric data and numerically expressed self-ratings of disability, provides a means for predicting disability with relatively good precision, using some index derivable from the audiogram. The aim of the present study was to consolidate or amend current prediction schemes based on tonal audiometric data by investigating the problem of differential bilateral weighting of threshold frequency through multiple regression performed on experimental data coming from an unbiased group of hearing impaired subjects. In addition to tonal thresholds, this corpus included simple, quantitative self-ratings for disability. The sample was considered to be a representative cross-section of adult hearing impaired ENT patients. The results indicate that prevailing bilateral weightings are likely to overestimate the importance of the worse ear. The regression results did not incorporate the usual threshold values and frequency weightings. The outcome nevertheless offered a multiple correlation coefficient that was higher than most correlations reported in the literature between disability ratings and threshold values.

Objective Binaural interaction can be investigated using auditory evoked potentials. A binaural interaction component can be derived from the auditory brainstem response (ABR–BIC) and is considered evidence for binaural interaction at the level of the brainstem. Although click ABR–BIC has been investigated thoroughly, data on 500 Hz tone-burst (TB) ABR–BICs are scarce. In this study, characteristics of click and 500 Hz TB ABR–BICs are described. Furthermore, reliability of both click and 500 Hz TB ABR–BIC are investigated. Methods Eighteen normal hearing young adults (eight women, ten men) were included. ABRs were recorded in response to clicks and 500 Hz TBs. ABR–BICs were derived by subtracting the binaural response from the sum of the monaural responses measured in opposite ears. Results Good inter-rater reliability is obtained for both click and 500 Hz TB ABR–BICs. The most reliable peak in click ABR–BIC occurs at a mean latency of 6.06 ms (SD 0.354 ms). Reliable 500 Hz TB ABR–BIC are obtained with a mean latency of 9.47 ms (SD 0.678 ms). Amplitudes are larger for 500 Hz TB ABR–BIC than for clicks. Conclusion The most reliable peak in click ABR–BIC occurs at the downslope of wave V. Five hundred Hertz TB ABR–BIC is characterized by a broad positivity occurring at the level of wave V. Significance The ABR–BIC is a useful technique to investigate binaural interaction in certain populations. Examples are bilateral hearing aid users, bilateral cochlear implant users and bimodal listeners. The latter refers to the combination of unilateral cochlear implantation and contralateral residual hearing. The majority of these patients have residual hearing in the low frequencies. The current study suggests that 500 Hz TB ABR–BIC may be a suitable technique to assess binaural interaction in this specific population of cochlear implant users.

The main objective of this study was to assess the associations between self-reported listening habits and perception of music and speech perception outcomes in quiet and noise for both unilateral cochlear implant (CI) users and bimodal (CI in one ear, hearing aid in contra-lateral ear) users. Information concerning music appreciation was gathered by means of a newly developed questionnaire. Moreover, audiological data (pure-tone audiometry, speech tests in noise and quiet) were gathered and the relationship between speech perception and music appreciation is studied. Bimodal users enjoy listening to music more in comparison with unilateral CI users. Also, music training within rehabilitation is still uncommon, while CI recipients believe that music training might be helpful to maximize their potential with current CI technology. Music training should not be exclusively reserved for the good speech performers. Therefore, a music training program (MTP) that consists of different difficulty levels should be developed. Hopefully, early implementation of MTP in rehabilitation programs can enable adult CI users to enjoy and appreciate music and to maximize their potential with commercially available technology. Furthermore, because bimodal users consider the bimodal stimulation to be the most enjoyable way to listen to music, CI users with residual hearing in the contra-lateral ear should be encouraged to continue wearing their hearing aid in that ear.

Objectives/Hypothesis: To evaluate the impact of a newborn hearing screening program on the management and outcome of deaf children and to identify underlying factors that may be responsible for the differences between high and low performing implanted children. Study Design: Retrospective cohort study of 391 implanted children in Flanders (Belgium). Methods: First, implanted children were sorted into two groups on account of screening age (early screened, n = 195 vs. late screened, n = 196). Both groups were compared with respect to several variables. Second, outcome of cochlear implantation was measured in terms of the child's speech perception and production skills (n = 355). A subgroup of high performing cochlear implant (CI) users was compared with low performing CI users with regard to several variables. Results: Early screened children differ significantly from late screened children with respect to age of hearing loss detection and age at cochlear implantation. Furthermore, early screening and implantation is associated with better auditory receptive skills and speech intelligibility. Additional impairments negatively influence both receptive and productive skills. In addition, children who communicate orally and wear bilateral cochlear implants perform better on speech production, whereas a better speech perception was found in children who became progressively deaf as opposed to congenitally deaf children. Conclusions: The results of this extensive study of profoundly deaf children with CIs in Flanders indicate that a newborn hearing screening program results in earlier intervention in deaf children, which beneficially influences the auditory receptive skills and speech intelligibility.

Rotational testing has been used in clinical practice to explore vestibular function. Frequently used stimulus algorithms include: sinusoidal harmonic acceleration test (SHAT), pseudorandom rotation test (PRRT), and velocity step test (VST). The aim of this study was to construct normative data as well as to evaluate the test-retest reliability of those rotational paradigms. One hundred and fifty subjects without vestibular history participated in the normative study. The SHAT was presented at 5 frequencies (0.01, 0.02, 0.05, 0.1, 0.2 Hz), whereas for the PRRT those frequencies were summed. The VST consisted of a rotation to the right and left and was administered twice. Thirty-two volunteers were retested to assess the test-retest reliability. Separate normative data were needed according to sex, stimulus type, and frequency for the SHAT and PRRT, and according to stimulus and direction for the VST. High reliability by means of the intraclass correlation coefficient (ICC) and the method error (ME) was obtained for the SHAT, PRRT, and VST gain, SHAT phase and asymmetry, and VST time constant parameters. The availability of data on the minimal detectable test-retest differences supports the evaluation of rotational responses on a retest session.

The present study utilized a commercially available multiple auditory steady-state response (ASSR) system to test normal hearing adults (n=55). The primary objective was to evaluate the impact of the mixed modulation (MM) and the novel proposed exponential AM(2)/FM stimuli on the signal-to-noise ratio (SNR) and threshold estimation accuracy, through a within-subject comparison. The second aim was to establish a normative database for both stimulus types. The results demonstrated that the AM(2)/FM and MM stimulus had a similar effect on the SNR, whereas the ASSR threshold results revealed that the AM(2)/FM produced better thresholds than the MM stimulus for the 500, 1000, and 4000 Hz carrier frequency. The mean difference scores to tones of 500, 1000, 2000, and 4000 Hz were for the MM stimulus: 20+/-12, 14+/-9, 10+/-8, and 12+/-8 dB; and for the AM(2)/FM stimulus: 18+/-13, 12+/-8, 11+/-8, and 10+/-8 dB, respectively. The current research confirms that the AM(2)/FM stimulus can be used efficiently to test normal hearing adults.

The aim of the present study was to construct and compare two caloric test protocols, one for water irrigation, and one for air insufflation. A set of reference data was constructed and tabulated as well as the intersubject variability. The effect of age, sex, ear, and temperature, as well as a possible priming effect and order effect were investigated. Forty-seven subjects (18-58 years) without otological or vestibular history participated. Four response parameters were investigated: slow component velocity (SCV), frequency, unilateral weakness (UW), and directional preponderance (DP). Statistically higher SCV values were obtained for water compared to air, with statistically higher standard deviations for SCV water values. No influences of age, sex, ear, or temperature could be demonstrated on any of the response parameters. The same applied for the presence of an order effect and a priming effect. Comparing the two protocols to one another led the present authors to favour water as the standard irrigation medium, and air only in situations where water is contra-indicated.

In order to develop a sensitive audiometric protocol for identifying ototoxicity in children, a retrospective study of 16 children treated with cisplatin and/or carboplatin was performed. Audiometric testing was done by means of pure-tone threshold audiometry (PTA), high-frequency audiometry (HFA), and distortion product otoacoustic emissions (DPOAEs). Cisplatin caused a sensorineural high-frequency hearing loss in the study group compared to the controls (p0.01). Sixty-six percent of the cisplatin patients had a grade 2 or 3 ototoxicity. However, ototoxicity was not found in the patients treated with carboplatin. An excellent correlation was found between DPOAE levels and results obtained by audiometry (r = 0.82). Patients exposed to cisplatin are at significant risk for the development of drug-induced sensorineural hearing loss. Because of the several advantages of DPOAEs (noninvasive, objective, rapid, easy to use, sensitive) this method should be added in the audiological follow-up in infants and toddlers.

The purpose of this study was to determine and to compare the overall intelligibility, articulation, resonance, and voice characteristics in children using cochlear implants (CI) and children using conventional hearing aids (HA). Nine prelingually deaf children using CI and six children with a prelingual severe hearing loss using HA, were selected to participate. Objective (DSI, nasalance scores) as well as subjective assessment techniques (perceptual evaluations) were used. Both the CI and HA children demonstrated normal vocal quality and resonance but showed the presence of articulation disorders. In the CI children, intelligibility was significantly better compared to the HA children. Significantly more phonetic and phonological disorders were present in the HA children. The results of this study show a poorer intelligibility of the HA children in comparison with the CI children which is probably due to the occurrence of significantly more phonetic and phonological disorders. Future detailed analysis in a larger sample of CI and HA children may help further clarify the issue of speech and voice characteristics and may demonstrate an important prognostic value.

To perform an assessment of the viability of cochlear implantation in a patient with superficial siderosis of the brain.Case review.Tertiary referral center.Patient with superficial siderosis of the brain.Cochlear implantation.Electrically evoked auditory brainstem responses and fitting strategy for cochlear implant based on patient's subjective responses.After some time, C levels and T levels showed a pattern comparable with the evoked auditory brainstem responses.Bilateral profound hearing loss after superficial siderosis of the brain is no absolute contraindication for implantation. Furthermore, evoked auditory brainstem measurements can potentially guide the fitting process of the implant in difficult cases.