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Background: A limited number of experiments have investigated the perception of strain compared to the voice qualities of breathiness and roughness despite its widespread occurrence in patients who have hyperfunctional voice disorders, adductor spasmodic dysphonia, and vocal fold paralysis among others., Objective: The purpose of this study is to determine the perceptual basis of strain through identification and exploration of acoustic and psychoacoustic measures., Methods: Twelve listeners evaluated the degree of strain for 28 dysphonic phonation samples on a five-point rating scale task. Computational estimates based on cepstrum, sharpness, and spectral moments (linear and transformed with auditory processing front-end) were correlated to the perceptual ratings., Results: Perceived strain was strongly correlated with cepstral peak prominence, sharpness, and a subset of the spectral metrics. Spectral energy distribution measures from the output of an auditory processing front-end (ie, excitation pattern and specific loudness pattern) accounted for 77-79% of the model variance for strained voices in combination with the cepstral measure., Conclusions: Modeling the perception of strain using an auditory front-end prior to acoustic analysis provides better characterization of the perceptual ratings of strain, similar to our prior work on breathiness and roughness. Results also provide evidence that the sharpness model of Fastl and Zwicker (2007) is one of the strong predictors of strain perception., (Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose Spectral modulation detection is an increasingly common assay of suprathreshold auditory perception and has been correlated with speech perception performance. Here, the potential effects of stimulus duration and stimulus presentation level on spectral modulation detection were investigated. Method Spectral modulation detection thresholds were measured as a function of modulation frequency in young, normal-hearing listeners. The standard stimulus was a bandpass noise, and signal stimuli were created by superimposing sinusoidal spectral modulation on the bandpass noise carrier. The modulation was sinusoidal on a log 2 frequency axis and a log 10 (dB) amplitude scale with a random starting phase (0-2π radians). In 1 experiment, stimulus durations were 50, 100, 200, or 400 ms (at fixed level 81 dB SPL). In a 2nd experiment, stimuli were presented at sensation levels of 10, 20, 30, 40, and 60 dB SL (fixed at a duration of 400 ms). Results Spectral modulation detection thresholds were similarly low for the 400- and 200-ms durations, increased slightly for the 100-ms duration, and increased markedly for the 50-ms duration. Thresholds were lowest for 40 dB SL; increased slightly for 20, 30, and 60 dB SL; and markedly higher for the 10-dB SL condition. Conclusions The increase in thresholds for the shortest durations and lowest sensational levels is consistent with previous investigations of auditory spectral profile analysis. The effects of presentation level and stimulus duration are important considerations in the context of understanding potential relationships between the perception of spectral cues and speech perception, when designing investigations and interpreting data related to spectral envelope perception, and in the context of models of auditory perception. As examples, 2 simple models based on auditory nerve output that have been used to explain spectrotemporal modulation in previous investigations produced an output inconsistent with the present results. Plain language summary Intensity variations across audio frequency lead to spectral shapes that are essential and sometimes signature features of various sounds in the environment, including speech. Here, we show how laboratory measures of spectral shape perception depend on presentation level and stimulus duration.

Purpose Growing evidence supports the inclusion of perceptual tests that quantify the processing of temporal fine structure (TFS) in clinical hearing assessment. Many tasks have been used to evaluate TFS in the laboratory that vary greatly in the stimuli used and whether the judgments require monaural or binaural comparisons of TFS. The purpose of this study was to compare laboratory measures of TFS for inclusion in a battery of suprathreshold auditory tests. A subset of available TFS tasks were selected on the basis of potential clinical utility and were evaluated using metrics that focus on characteristics important for clinical use. Method TFS measures were implemented in replication of studies that demonstrated clinical utility. Monaural, diotic, and dichotic measures were evaluated in 11 young listeners with normal hearing. Measures included frequency modulation (FM) tasks, harmonic frequency shift detection, interaural phase difference (TFS-low frequency), interaural time difference (ITD), monaural gap duration discrimination, and tone detection in noise with and without a difference in interaural phase (N 0 S 0 , N 0 S π ). Data were compared with published results and evaluated with metrics of consistency and efficiency. Results Thresholds obtained were consistent with published data. There was no evidence of predictive relationships among the measures consistent with a homogenous group. The most stable tasks across repeated testing were TFS-low frequency, diotic and dichotic FM, and N 0 S π . Monaural and diotic FM had the lowest normalized variance and were the most efficient accounting for differences in total test duration, followed by ITD. Conclusions Despite a long stimulus duration, FM tasks dominated comparisons of consistency and efficiency. Small differences separated the dichotic tasks FM, ITD, and N 0 S π . Future comparisons following procedural optimization of the tasks will evaluate clinical efficiency in populations with impairment.

Background: The perception of pediatric voice quality has been investigated using clinical protocols developed for adult voices and acoustic analyses designed to identify important physical parameters associated with normal and dysphonic pediatric voices. Laboratory investigations of adult dysphonia have included sophisticated methods, including a psychoacoustic approach that involves a single-variable matching task (SVMT), characterized by high inter- and intra-listener reliability, and analyses that include bio-inspired models of auditory perception that have provided valuable information regarding adult voice quality., Objectives: To establish the utility of a psychoacoustic approach to the investigation of voice quality perception in the context of pediatric voices?, Methods: Six listeners judged the breathiness of 20 synthetic vowel stimuli using an SVMT. To support comparisons with previous data, stimuli were modeled after four pediatric speakers and synthesized using Klatt with five parameter settings that influence the perception of breathiness. The population average breathiness judgments were modeled with acoustic measures of loudness ratio, pitch strength, and cepstral peak., Results: Listeners reliably judged the perceived breathiness of pediatric voices, as with previous investigations of breathiness in adult dysphonic voices. Breathiness judgments were accurately modeled by loudness ratio (r 2  = 0.93), pitch strength (r 2  = 0.91), and cepstral peak (r 2  = 0.82). Model accuracy was not affected significantly by including stimulus fundamental frequency and was slightly higher for pediatric than for adult voices., Conclusions: The SVMT proved robust for pediatric voices spanning a wide range of breathiness. The data indicate that this is a promising approach for future investigation of pediatric voice quality., (Copyright © 2019 The Voice Foundation. Published by Elsevier Inc. All rights reserved.)

Purpose: The goal was to evaluate the potential effects of increasing hearing loss and advancing age on spectral envelope perception., Method: Spectral modulation detection was measured as a function of spectral modulation frequency from 0.5 to 8.0 cycles/octave. The spectral modulation task involved discrimination of a noise carrier (3 octaves wide from 400 to 3200 Hz) with a flat spectral envelope from a noise having a sinusoidal spectral envelope across a logarithmic audio frequency scale. Spectral modulation transfer functions (SMTFs; modulation threshold vs. modulation frequency) were computed and compared 4 listener groups: young normal hearing, older normal hearing, older with mild hearing loss, and older with moderate hearing loss. Estimates of the internal spectral contrast were obtained by computing excitation patterns., Results: SMTFs for young listeners with normal hearing were bandpass with a minimum modulation detection threshold at 2 cycles/octave, and older listeners with normal hearing were remarkably similar to those of the young listeners. SMTFs for older listeners with mild and moderate hearing loss had a low-pass rather than a bandpass shape. Excitation patterns revealed that limited spectral resolution dictated modulation detection thresholds at high but not low spectral modulation frequencies. Even when factoring out (presumed) differences in frequency resolution among groups, the spectral envelope perception was worse for the group with moderate hearing loss than the other 3 groups., Conclusions: The spectral envelope perception as measured by spectral modulation detection thresholds is compromised by hearing loss at higher spectral modulation frequencies, consistent with predictions of reduced spectral resolution known to accompany sensorineural hearing loss. Spectral envelope perception is not negatively impacted by advancing age at any spectral modulation frequency between 0.5 and 8.0 cycles/octave.

Objectives: This study was designed to evaluate binaural temporal processing in young and older adults using a binaural masking level difference (BMLD) paradigm. Using behavioral and electrophysiological measures within the same listeners, a series of stimulus manipulations was used to evaluate the relative contribution of binaural temporal fine-structure and temporal envelope cues. We evaluated the hypotheses that age-related declines in the BMLD task would be more strongly associated with temporal fine-structure than envelope cues and that age-related declines in behavioral measures would be correlated with cortical auditory evoked potential (CAEP) measures., Design: Thirty adults participated in the study, including 10 young normal-hearing, 10 older normal-hearing, and 10 older hearing-impaired adults with bilaterally symmetric, mild-to-moderate sensorineural hearing loss. Behavioral and CAEP thresholds were measured for diotic (So) and dichotic (Sπ) tonal signals presented in continuous diotic (No) narrowband noise (50-Hz wide) maskers. Temporal envelope cues were manipulated by using two different narrowband maskers; Gaussian noise (GN) with robust envelope fluctuations and low-noise noise (LNN) with minimal envelope fluctuations. The potential to use temporal fine-structure cues was controlled by varying the signal frequency (500 or 4000 Hz), thereby relying on the natural decline in phase-locking with increasing frequency., Results: Behavioral and CAEP thresholds were similar across groups for diotic conditions, while the masking release in dichotic conditions was larger for younger than for older participants. Across all participants, BMLDs were larger for GN than LNN and for 500-Hz than for 4000-Hz conditions, where envelope and fine-structure cues were most salient, respectively. Specific age-related differences were demonstrated for 500-Hz dichotic conditions in GN and LNN, reflecting reduced binaural temporal fine-structure coding. No significant age effects were observed for 4000-Hz dichotic conditions, consistent with similar use of binaural temporal envelope cues across age in these conditions. For all groups, thresholds and derived BMLD values obtained using the behavioral and CAEP methods were strongly correlated, supporting the notion that CAEP measures may be useful as an objective index of age-related changes in binaural temporal processing., Conclusions: These results demonstrate an age-related decline in the processing of binaural temporal fine-structure cues with preserved temporal envelope coding that was similar with and without mild-to-moderate peripheral hearing loss. Such age-related changes can be reliably indexed by both behavioral and CAEP measures in young and older adults.

Spectral modulation transfer functions (SMTFs) were measured in 49 young (18-35 years of age) normal-hearing listeners. Noise carriers spanned six octaves from 200 to 12 800 Hz. Sinusoidal (on a log-amplitude scale) spectral modulation with random starting phase was superimposed on the carrier at spectral modulation frequencies of 0.25, 0.5, 1.0, 2.0, 4.0, and 8.0 cycles/octave. Modulation detection thresholds (in dB) yielded SMTFs that were bandpass in nature, consistent with previous investigations reporting data for only a few subjects. Thresholds were notably consistent across subjects despite minimal practice. Population statistics are reported that may serve as reference data for future studies.

Young adults with normal hearing (YNH) can improve their sensitivity to basic acoustic features with practice. However, it is not known to what extent the influence of the same training regimen differs between YNH listeners and older listeners with hearing impairment (OHI)--the largest population seeking treatment in audiology clinics. To examine this issue, we trained OHI listeners on a basic auditory task (spectral modulation detection) using a training regimen previously administered to YNH listeners (≈ 1 h/session for seven sessions on a single condition). For the trained conditions on which pretraining performance was not already at asymptote, the YNH listeners who received training learned more than matched controls who received none, but that learning did not generalize to any untrained spectral modulation frequency. In contrast, the OHI-trained listeners and controls learned similar amounts on the trained condition, implying no effect of the training itself. However, surprisingly the OHI-trained listeners improved over the training phase and on an untrained spectral modulation frequency. These population differences suggest that learning consolidated more slowly, and that training modified an aspect of processing that had broader tuning to spectral modulation frequency, in OHI than YNH listeners. More generally, these results demonstrate that conclusions about perceptual learning that come from examination of one population do not necessarily apply to another.

The NIH Toolbox project has assembled measurement tools to assess a wide range of human perception and ability across the lifespan. As part of this initiative, a small but comprehensive battery of auditory tests has been assembled. The main tool of this battery, pure-tone thresholds, measures the ability of people to hear at specific frequencies. Pure-tone thresholds have long been considered the "gold standard" of auditory testing, and are normally obtained in a clinical setting by highly trained audiologists. For the purposes of the Toolbox project, an automated procedure (NIH Toolbox Threshold Hearing Test) was developed that allows nonspecialists to administer the test reliably. Three supplemental auditory tests are also included in the Toolbox auditory test battery: assessment of middle-ear function (tympanometry), speech perception in noise (the NIH Toolbox Words-in-Noise Test), and self-assessment of hearing impairment (the NIH Toolbox Hearing Handicap Inventory Ages 18-64 and the NIH Toolbox Hearing Handicap Inventory Ages 64+). Tympanometry can help differentiate conductive from sensorineural pathology. The NIH Toolbox Words-in-Noise Test measures a listener's ability to perceive words in noisy situations. This ability is not necessarily predicted by a person's pure-tone thresholds; some people with normal hearing have difficulty extracting meaning from speech sounds heard in a noisy context. The NIH Toolbox Hearing Handicap Inventory focuses on how a person's perceived hearing status affects daily life. The test was constructed to include emotional and social/situational subscales, with specific questions about how hearing impairment may affect one's emotional state or limit participation in specific activities. The 4 auditory tests included in the Toolbox auditory test battery cover a range of auditory abilities and provide a snapshot of a participant's auditory capacity.

Age-related hearing impairment (ARHI), or presbycusis, is a common condition of the elderly that results in significant communication difficulties in daily life. Clinically, it has been defined as a progressive loss of sensitivity to sound, starting at the high frequencies, inability to understand speech, lengthening of the minimum discernable temporal gap in sounds, and a decrease in the ability to filter out background noise. The causes of presbycusis are likely a combination of environmental and genetic factors. Previous research into the genetics of presbycusis has focused solely on hearing as measured by pure-tone thresholds. A few loci have been identified, based on a best ear pure-tone average phenotype, as having a likely role in susceptibility to this type of hearing loss; and GRM7 is the only gene that has achieved genome-wide significance. We examined the association of GRM7 variants identified from the previous study, which used an European cohort with Z-scores based on pure-tone thresholds, in a European-American population from Rochester, NY (N = 687), and used novel phenotypes of presbycusis. In the present study mixed modeling analyses were used to explore the relationship of GRM7 haplotype and SNP genotypes with various measures of auditory perception. Here we show that GRM7 alleles are associated primarily with peripheral measures of hearing loss, and particularly with speech detection in older adults., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Natural sounds are characterized by complex patterns of sound intensity distributed across both frequency (spectral modulation) and time (temporal modulation). Perception of these patterns has been proposed to depend on a bank of modulation filters, each tuned to a unique combination of a spectral and a temporal modulation frequency. There is considerable physiological evidence for such combined spectrotemporal tuning. However, direct behavioral evidence is lacking. Here we examined the processing of spectrotemporal modulation behaviorally using a perceptual-learning paradigm. We trained human listeners for ∼1 h/d for 7 d to discriminate the depth of spectral (0.5 cyc/oct; 0 Hz), temporal (0 cyc/oct; 32 Hz), or upward spectrotemporal (0.5 cyc/oct; 32 Hz) modulation. Each trained group learned more on their respective trained condition than did controls who received no training. Critically, this depth-discrimination learning did not generalize to the trained stimuli of the other groups or to downward spectrotemporal (0.5 cyc/oct; -32 Hz) modulation. Learning on discrimination also led to worsening on modulation detection, but only when the same spectrotemporal modulation was used for both tasks. Thus, these influences of training were specific to the trained combination of spectral and temporal modulation frequencies, even when the trained and untrained stimuli had one modulation frequency in common. This specificity indicates that training modified circuitry that had combined spectrotemporal tuning, and therefore that circuits with such tuning can influence perception. These results are consistent with the possibility that the auditory system analyzes sounds through filters tuned to combined spectrotemporal modulation.

Normal sensory perception requires the ability to detect and identify patterns of activity distributed across the receptor surface. In the visual system, the ability to perceive these patterns across the retina improves with training. This learning differs in magnitude for different trained stimuli and does not generalize to untrained spatial frequencies or retinal locations. Here, we asked whether training to detect patterns of activity across the cochlea yields learning with similar characteristics. Differences in learning between the visual and auditory systems would be inconsistent with the suggestion that the ability to detect these patterns is limited by similar constraints in these two systems. We trained three groups of normal-hearing listeners to detect spectral envelopes with a sinusoidal shape (spectral modulation) at 0.5, 1, or 2 cycles/octave and compared the performance of each group to that of a separate group that received no training. On average, as the trained spectral modulation frequency increased, the magnitude of training-induced improvement and the time to reach asymptotic performance decreased, while the tendency for performance to worsen within a training session increased. The training-induced improvements did not generalize to untrained spectral modulation frequencies or untrained carrier spectra. Thus, for both visual-spatial and auditory spectral modulation detection, learning depended upon and was specific to analogous features of the trained stimulus. Such similarities in learning could arise if, as has been suggested, similar constraints limit the ability to detect patterns across the receptor surface between the auditory and visual systems.

Experiments to study voice quality have typically used rating scales or direct magnitude estimation to obtain listener judgments. Unfortunately, the data obtained using these tasks are context dependent, which makes it difficult to compare perceptual judgments of voice quality across experiments. The present experiment describes a simple matching task to quantify voice quality. The data obtained through this task were compared to perceptual judgments obtained using rating scale and direct magnitude estimation tasks to determine whether the three tasks provide equivalent perceptual distances across stimuli. Ten synthetic vowel continua that varied in terms of their aspiration noise were evaluated for breathiness using each of the three tasks. Linear and nonlinear regressions were used to compare the perceptual distances between stimuli obtained through each technique. Results show that the perceptual distances estimated from matching and direct magnitude estimation task are similar, but both differ from the rating scale task, suggesting that the matching task provides perceptual distances with ratio-level measurement properties. The matching task is advantageous for measurement of vocal quality because it provides reliable measurement with ratio-level scale properties. It allows the use of a fixed reference signal for all comparisons, thus allowing researchers to directly compare findings across different experiments., (Copyright (c) 2010 The Voice Foundation. All rights reserved.)

Speech understanding by cochlear implant listeners may be limited by their ability to perceive complex spectral envelopes. Here, spectral envelope perception was characterized by spectral modulation transfer functions in which modulation detection thresholds became poorer with increasing spectral modulation frequency (SMF). Thresholds at low SMFs, less likely to be influenced by spectral resolution, were correlated with vowel and consonant identifications [Litvak, L. M. et al. (2008). J. Acoust. Soc. Am. 122, 982-991] for the same listeners; while thresholds at higher SMFs, more likely to be affected by spectral resolution, were not. Results indicate that the perception of broadly spaced spectral features is important for speech perception.

Sound localization cues generally include interaural time difference, interaural intensity difference, and spectral cues. The purpose of this study is to investigate the important spectral cues involved in so-called head related transfer functions (HRTFs) using a combination of HRTF analyses and a virtual sound localization (VSL) experiment. Previous psychoacoustical and physiological studies have both suggested the existence of spectral modulation frequency (SMF) channels for analyzing spectral information (e.g., the spectral cues coded in HRTFs). SMFs are in a domain related to the Fourier transform of HRTFs. The relationship between various SMF regions and sound localization was tested here by filtering or enhancing HRTFs in the SMF domain under a series of conditions using a VSL experiment. Present results revealed that azimuth localization was not significantly affected by HRTF manipulation. Applying notch filters between 0.1 and 0.4 cyclesoctave or between 0.35 and 0.65 cyclesoctave resulted in significantly less accurate elevation responses at low elevations, while spectral enhancement in these two SMF regions did not produce a significant change in sound localization. Likewise, low-pass filtering at 2 cyclesoctave did not significantly influence localization accuracy, suggesting that the major cues for sound localization are in the SMF region below 2 cyclesoctave.

Purpose: Acoustic and perceptual quantification of vocal strain has been a vexing problem for years. To increase measurement rigor, a suitable single-variable matching stimulus for strain was developed and validated, based on the matching stimulus used previously for breathy and rough voice qualities. Method: A set of 21 comparison stimuli for a single-variable matching task (SVMT) was synthesized based on a speech-shaped sawtooth waveform mixed with speech-shaped noise. Variable bandpass filter gain in mid-to-high frequencies achieved a wide range of computed sharpness (in constant sharpness steps) and served as the independent variable for the SVMT. Ten natural /[open back unrounded vowel]/ stimuli with a wide range of the primary voice quality of strain and a minimum of breathiness or roughness were selected and assessed using the SVMT. Natural voice samples and synthetic comparison stimuli were also assessed using a perceptual magnitude estimation (ME) task. Results: ME data validated the correspondence of the set of comparison stimuli to varying perceived strain. Perceived strain magnitudes of the comparison stimuli increased significantly and linearly with computed sharpness (r[superscript 2] = 0.99). A linear regression revealed that strain matching values were significantly predicted by computed sharpness (r[superscript 2] = 0.96) and perceived strain magnitudes (r[superscript 2] = 0.95) of the natural voice stimuli. Conclusion: The perception of vocal strain is strongly associated with computed sharpness and is captured accurately and precisely using an SVMT, in which the independent variable is the bandpass filter gain (in steps of equal sharpness) applied to the comparison stimuli.

Purpose: Vocal roughness is often present in many voice disorders but the assessment of roughness mainly depends on the subjective auditory-perceptual evaluation and lacks acoustic correlates. This study aimed to apply the concept of roughness in general sound quality perception to vocal roughness assessment and to characterize the relationship between vocal roughness and temporal envelop fluctuation measures obtained from an auditory model. Method: Ten /[open back unrounded vowel]/ recordings with a wide range of roughness were selected from an existing database. Ten listeners rated the roughness of the recordings in a single-variable matching task. Temporal envelope fluctuations of the recordings were analyzed with an auditory processing model of amplitude modulation that utilizes a modulation filterbank of different modulation frequencies. Pitch strength and the smoothed cepstral peak prominence were also obtained for comparison. Results: Individual simple regression models yielded envelope standard deviation from a modulation filter with a low center frequency (64.3 Hz) as a statistically significant predictor of vocal roughness with a strong coefficient of determination (r[subscript 2] = 0.80). Pitch strength and CPPS were not significant predictors of roughness. Conclusion: This result supports the possible utility of envelope fluctuation measures from an auditory model as objective correlates of vocal roughness.

Head movement plays a vital role in auditory processing by contributing to spatial awareness and the ability to identify and locate sound sources. Here we investigate head-orienting behaviors using a dual-task experimental paradigm to measure: (a) localization of a speech source; and (b) detection of meaningful speech (numbers), within a complex acoustic background. Ten younger adults with normal hearing and 20 older adults with mild-to-severe sensorineural hearing loss were evaluated in the free field on two headmovement conditions: (1) head fixed to the front and (2) head moving to a source location; and two context conditions: (1) with audio only or (2) with audio plus visual cues. Head-tracking analyses quantified the target location relative to head location, as well as the peak velocity during head movements. Evaluation of head-orienting behaviors revealed that both groups tended to undershoot the auditory target for targets beyond 60° in azimuth. Listeners with hearing loss had higher head-turn errors than the normal-hearing listeners, even when a visual location cue was provided. Digit detection accuracy was better for the normal-hearing than hearing-loss groups, with a main effect of signal-to-noise ratio (SNR). When performing the dual-task paradigm in the most difficult listening environments, participants consistently demonstrated a wait-and-listen head-movement strategy, characterized by a short pause during which they maintained their head orientation and gathered information before orienting to the target location. [ABSTRACT FROM AUTHOR]

Older adults with normal hearing or with age-related hearing loss face challenges when listening to speech in noisy environments. To better serve individuals with communication difficulties, precision diagnostics are needed to characterize individuals' auditory perceptual and cognitive abilities beyond pure tone thresholds. These abilities can be heterogenous across individuals within the same population. The goal of the present study is to consider the suprathreshold variability and develop characteristic profiles for older adults with normal hearing (ONH) and with hearing loss (OHL). Auditory perceptual and cognitive abilities were tested on ONH (n = 20) and OHL (n = 20) on an abbreviated test battery using portable automated rapid testing. Using cluster analyses, three main profiles were revealed for each group, showing differences in auditory perceptual and cognitive abilities despite similar audiometric thresholds. Analysis of variance showed that ONH profiles differed in spatial release from masking, speech-in-babble testing, cognition, tone-in-noise, and binaural temporal processing abilities. The OHL profiles differed in spatial release from masking, speech-in-babble testing, cognition, and tolerance to background noise performance. Correlation analyses showed significant relationships between auditory and cognitive abilities in both groups. This study showed that auditory perceptual and cognitive deficits can be present to varying degrees in the presence of audiometrically normal hearing and among listeners with similar degrees of hearing loss. The results of this study inform the need for taking individual differences into consideration and developing targeted intervention options beyond pure tone thresholds and speech testing. [ABSTRACT FROM AUTHOR]

Purpose: This report describes a hearing device and corresponding fitting protocol designed for use in a transitional intervention for debilitating loudnessbased hyperacusis. Method: The intervention goal is to transition patients with hyperacusis from their typical counterproductive sound avoidance behaviors (i.e., sound attenuation and limited exposure to healthy low-level sounds) into beneficial sound therapy treatment that can expand their dynamic range to the point where they can tolerate everyday sounds and experience an improved quality of life. This requires a combination of counseling and sound therapy, the latter of which is provided via the hearing device technology, signal processing, and precision fitting approach described in this report. The device combines a miniature behind-the-ear sound processor and a custom earpiece designed to maximize the attenuation of external sounds. Output-limiting loudness suppression is used to restrict exposure to offending high-level sounds while unity gain amplification maximizes exposure to healthy and tolerable lower level sounds. The fitting process includes measurement of the real-ear unaided response, the realear measurement (REM) system noise floor, the real-ear occluded response, real-ear insertion gain, and the output limit. With these measurements, the device can achieve the prescribed unity gain needed to provide transparent access to comfortable sound levels. It also supports individualized configuration of the therapeutic noise from an on-board sound generator and adaptive output limiting based on treatment-induced increases in dynamic range. Results and Conclusion: The utility of this device and fitting protocol, in combination with structured counseling, is highlighted in the outcomes of a successful 6-month trial of the transitional intervention described in a companion report in this issue. [ABSTRACT FROM AUTHOR]

Purpose: This report provides the experimental, clinical, theoretical, and historical background that motivated a patented transitional intervention and its implementation and evaluation in a field trial for mitigation of debilitating loudness based hyperacusis (LH). Background and Rationale: Barriers for ameliorating LH, which is differentiated here from other forms of hyperacusis, are delineated, including counterproductive management and treatment strategies that may exacerbate the condition. Evidence for hyper-gain central auditory processes as the bases for LH and the associated LH-induced distress and stress responses are presented. This presentation is followed by an overview of prior efforts to use counseling and therapeutic sound as interventional tools for recalibrating the hyper-gain LH response. We also consider previous efforts to use output-limiting sound protection devices in the management of LH. This historical background lays the foundation for our transitional intervention protocol and its implementation and evaluation in a field trial. Conclusions: The successful implementation and evaluation of a transitional intervention, which we document in the outcomes of a companion proof-of concept field trial in this issue, build on our prior efforts and those of others to understand, manage, and treat hyperacusis. These efforts to overcome significant barriers and vexing long-standing challenges in the management and treatment of LH, as reviewed here, are the pillars of the transitional intervention and its primary components, namely, counseling combined with protective sound management and therapeutic sound, which we detail in separate reports in this issue. [ABSTRACT FROM AUTHOR]

Purpose: We present results from a 6-month field trial of a transitional intervention for debilitating primary hyperacusis, including a combination of structured counseling; promotion of safe, comfortable, and healthy sound exposure; and therapeutic broadband sound from sound generators. This intervention is designed to overcome barriers to successful delivery of therapeutic sound as a tool to downregulate neural hyperactivity in the central auditory pathways (i.e., the maladaptive mechanism believed to account for primary hyperacusis) and, together with the counseling, reduce the associated negative emotional and physiological reactions to debilitating hyperacusis. Method: Twelve adults with normal or near-normal audiometric thresholds, complaints consistent with their pretreatment loudness discomfort levels ≤ 75 dB HL at multiple frequencies, and hearing questionnaire scores ≥ 24 completed the sound therapy–based intervention. The low-level broadband therapeutic sound was delivered by ear-level devices fitted bilaterally with either occluding earpieces and output-limiting loudness suppression (LS; to limit exposure to offensive sound levels) or open domes to maximize comfort and exposure to sound therapy. Thresholds for LS (primary outcome) were incrementally adjusted across six monthly visits based on treatment-driven change in loudness judgments for running speech in sound field. Secondary outcomes included categorical loudness judgments, speech understanding, and questionnaires to assess the hyperacusis problem, quality of life, and depression. An exit survey assessed satisfaction with and benefit from the intervention and the counseling, therapeutic sound, and LS components. Results: The mean change in LS (34.8 dB) was highly significant (effect size = 2.045). Eleven of 12 participants achieved ≥ 16-dB change in LS, consistent with highly significant change in sound-based questionnaire scores. Exit surveys indicated satisfaction with and benefit from the intervention. Conclusion: The transitional intervention was successful in improving the hyperacusis conditions of 11 of 12 study participants while reducing their sound avoidance behaviors and reliance on sound protection. [ABSTRACT FROM AUTHOR]

Remote testing of auditory function can be transformative to both basic research and hearing healthcare; however, historically, many obstacles have limited remote collection of reliable and valid auditory psychometric data. Here, we report performance on a battery of auditory processing tests using a remotely administered system, Portable Automatic Rapid Testing. We compare a previously reported dataset collected in a laboratory setting with the same measures using uncalibrated, participant-owned devices in remote settings (experiment 1, n = 40) remote with and without calibrated hardware (experiment 2, n = 36) and laboratory with and without calibrated hardware (experiment 3, n = 58). Results were well-matched across datasets and had similar reliability, but overall performance was slightly worse than published norms. Analyses of potential nuisance factors such as environmental noise, distraction, or lack of calibration failed to provide reliable evidence that these factors contributed to the observed variance in performance. These data indicate feasibility of remote testing of suprathreshold auditory processing using participants' own devices. Although the current investigation was limited to young participants without hearing difficulties, its outcomes demonstrate the potential for large-scale, remote hearing testing of more hearing-diverse populations both to advance basic science and to establish the clinical viability of auditory remote testing. [ABSTRACT FROM AUTHOR]

(1) Background: Difficulty hearing in noise is exacerbated in older adults. Older adults are more likely to have audiometric hearing loss, although some individuals with normal pure-tone audiograms also have difficulty perceiving speech in noise. Additional variables also likely account for speech understanding in noise. It has been suggested that one important class of variables is the ability to process auditory information once it has been detected. Here, we tested a set of these "suprathreshold" auditory processing abilities and related them to performance on a two-part test of speech understanding in competition with and without spatial separation of the target and masking speech. Testing was administered in the Portable Automated Rapid Testing (PART) application developed by our team; PART facilitates psychoacoustic assessments of auditory processing. (2) Methods: Forty-one individuals (average age 51 years), completed assessments of sensitivity to temporal fine structure (TFS) and spectrotemporal modulation (STM) detection via an iPad running the PART application. Statistical models were used to evaluate the strength of associations between performance on the auditory processing tasks and speech understanding in competition. Age and pure-tone-average (PTA) were also included as potential predictors. (3) Results: The model providing the best fit also included age and a measure of diotic frequency modulation (FM) detection but none of the other potential predictors. However, even the best fitting models accounted for 31% or less of the variance, supporting work suggesting that other variables (e.g., cognitive processing abilities) also contribute significantly to speech understanding in noise. (4) Conclusions: The results of the current study do not provide strong support for previous suggestions that suprathreshold processing abilities alone can be used to explain difficulties in speech understanding in competition among older adults. This discrepancy could be due to the speech tests used, the listeners tested, or the suprathreshold tests chosen. Future work with larger numbers of participants is warranted, including a range of cognitive tests and additional assessments of suprathreshold auditory processing abilities. [ABSTRACT FROM AUTHOR]

Correlated sounds presented to two ears are perceived as compact and centrally lateralized, whereas decorrelation between ears leads to intracranial image widening. Though most listeners have fine resolution for perceptual changes in interaural correlation (IAC), some investigators have reported large variability in IAC thresholds, and some normal-hearing listeners even exhibit seemingly debilitating IAC thresholds. It is unknown whether or not this variability across individuals and outlier manifestations are a product of task difficulty, poor training, or a neural deficit in the binaural auditory system. The purpose of this study was first to identify listeners with normal and abnormal IAC resolution, second to evaluate the neural responses elicited by IAC changes, and third to use a well-established model of binaural processing to determine a potential explanation for observed individual variability. Nineteen subjects were enrolled in the study, eight of whom were identified as poor performers in the IACthreshold task. Global scalp responses (N1 and P2 amplitudes of an auditory change complex) in the individuals with poor IAC behavioral thresholds were significantly smaller than for listeners with better IAC resolution. Source-localized evoked responses confirmed this group effect in multiple subdivisions of the auditory cortex, including Heschl's gyrus, planum temporale, and the temporal sulcus. In combination with binaural modeling results, this study provides objective electrophysiological evidence of a binaural processing deficit linked to internal noise, that corresponds to very poor IAC thresholds in listeners that otherwise have normal audiometric profiles and lack spatial hearing complaints. [ABSTRACT FROM AUTHOR]

Purpose: Improving the ability to listen efficiently in noisy environments is a critical goal for hearing rehabilitation. However, understanding of the impact of difficult listening conditions on language processing is limited. The current study evaluated the neural processes underlying semantics in challenging listening conditions. Method: Thirty adults with normal hearing completed an auditory sentence processing task in 4-talker babble. Eventrelated brain potentials were elicited by the final word in highor low-context sentences, where the final word was either highly expected or not expected, followed by a 4-alternative forced-choice response with either longer (1,000 ms), middle (700 ms), or shorter (400 ms) response time deadlines (RTDs). Results: Behavioral accuracy was reduced, and reactions times were faster for shorter RTDs. N400 amplitudes, reflecting ease of lexical access, were larger when elicited by target words in low-context sentences followed by shorter compared with longer RTDs. Conclusions: These results reveal that more neural resources are allocated for semantic processing/lexical access when listening difficulty increases. Differences between RTDs may reflect increased attentional allocation for shorter RTDs. These findings suggest that situational listening demands can impact the demands for cognitive resources engaged in language processing, which could significantly impact listener experiences across environments. [ABSTRACT FROM AUTHOR]

A psychophysical matching paradigm has been used to better quantify voice quality under laboratory conditions. The goals of this study were to establish which of two candidate comparison stimuli would best ensure that the range of perceived vocal roughness could be adequately bracketed using a matching task and to provide a general solution to the problem of estimating vocal roughness. Psychometric functions for roughness matching indicated that a speech-like sawtooth-plus-noise complex (20 dB signal-to-noise ratio) amplitude modulated by a sinusoidal function raised to the 4th power yielded a comparison stimulus with a perceptual dynamic range well suited for roughness matching. [ABSTRACT FROM AUTHOR]

The goal of this study was to measure the effects of global spectral manipulations on vowel identification by progressively high-pass filtering vowel stimuli in the spectral modulation domain. Twelve American-English vowels, naturally spoken by a female talker, were subjected to varied degrees of high-pass filtering in the spectral modulation domain, with cutoff frequencies of 0.0, 0.5, 1.0, 1.5, and 2.0 cycles/octave. Identification performance for vowels presented at 70 dB sound pressure level with and without spectral modulation filtering was measured for five normal-hearing listeners. Results indicated that vowel identification performance was progressively degraded as the spectral modulation cutoff frequency increased. Degradation of vowel identification was greater for back vowels than for front or central vowels. Detailed acoustic analyses indicated that spectral modulation filtering resulted in a more crowded vowel space (F1×F2), reduced spectral contrast, and reduced spectral tilt relative to the original unfiltered vowels. Changes in the global spectral features produced by spectral modulation filtering were associated with substantial reduction in vowel identification. The results indicated that the spectral cues critical for vowel identification were represented by spectral modulation frequencies below 2 cycles/octave. These results are considered in terms of the interactions among spectral shape perception, spectral smearing, and speech perception. [ABSTRACT FROM AUTHOR]

The auditory system relies on extraordinarily precise timing cues for the accurate perception of speech, music, and object identification. Epidemiological research has documented the age-related progressive decline in hearing sensitivity that is known to be a major health concern for the elderly. Although smaller investigations indicate that auditory temporal processing also declines with age, such measures have not been included in larger studies. Temporal gap detection thresholds (TGDTs; an index of auditory temporal resolution) measured in 1071 listeners (aged 18–98 years) were shown to decline at a minimum rate of 1.05 ms (15%) per decade. Age was a significant predictor of TGDT when controlling for audibility (partial correlation) and when restricting analyses to persons with normal-hearing sensitivity (n = 434). The TGDTs were significantly better for males (3.5 ms; 51%) than females when averaged across the life span. These results highlight the need for indices of temporal processing in diagnostics, as treatment targets, and as factors in models of aging. [ABSTRACT FROM AUTHOR]