Comparison of Psychometric Functions Measured Using Remote Testing and Laboratory Testing.

The use of remote testing to collect behavioral data has been on the rise, especially after the COVID-19 pandemic. Here we present psychometric functions for a commonly used speech corpus obtained in remote testing and laboratory testing conditions on young normal hearing listeners in the presence of different types of maskers. Headphone use for the remote testing group was checked by supplementing procedures from prior literature using a Huggins pitch task. Results revealed no significant differences in the measured thresholds using the remote testing and laboratory testing conditions for all the three masker types. Also, the thresholds measured obtained in these two conditions were strongly correlated for a different group of young normal hearing listeners. Based on the results, excellent outcomes on auditory threshold measurements where the stimuli are presented both at levels lower than and above an individual's speech-recognition threshold can be obtained by remotely testing the listeners.

Midlife Speech Perception Deficits: Impact of Extended High-Frequency Hearing, Peripheral Neural Function, and Cognitive Abilities.

OBJECTIVES: The objectives of the present study were to investigate the effects of age-related changes in extended high-frequency (EHF) hearing, peripheral neural function, working memory, and executive function on speech perception deficits in middle-aged individuals with clinically normal hearing. DESIGN: We administered a comprehensive assessment battery to 37 participants spanning the age range of 20 to 56 years. This battery encompassed various evaluations, including standard and EHF pure-tone audiometry, ranging from 0.25 to 16 kHz. In addition, we conducted auditory brainstem response assessments with varying stimulation rates and levels, a spatial release from masking (SRM) task, and cognitive evaluations that involved the Trail Making test (TMT) for assessing executive function and the Abbreviated Reading Span test (ARST) for measuring working memory. RESULTS: The results indicated a decline in hearing sensitivities at EHFs and an increase in completion times for the TMT with age. In addition, as age increased, there was a corresponding decrease in the amount of SRM. The declines in SRM were associated with age-related declines in hearing sensitivity at EHFs and TMT performance. While we observed an age-related decline in wave I responses, this decline was primarily driven by age-related reductions in EHF thresholds. In addition, the results obtained using the ARST did not show an age-related decline. Neither the auditory brainstem response results nor ARST scores were correlated with the amount of SRM. CONCLUSIONS: These findings suggest that speech perception deficits in middle age are primarily linked to declines in EHF hearing and executive function, rather than cochlear synaptopathy or working memory.

Assessing subclinical hearing loss in musicians and nonmusicians using auditory brainstem responses and speech perception measures.

In this study, the physiological and perceptual correlates of auditory function in student musicians and nonmusicians with normal hearing thresholds were investigated. The measures involved were auditory brainstem responses as a function of stimulation rate, spatial release from masking, and word intensity rollover functions. The results indicated that as the stimulation rate was increased, the wave I amplitude reductions were more abrupt in musicians than in nonmusicians. However, no significant group differences were observed for speech tasks. There were also no significant correlations between the results of speech perception and the measures of peripheral neural function.

Comparison of Speech, Spatial, and Qualities of Hearing Scale (SSQ) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) Questionnaires in a Large Cohort of Self-Reported Normal-Hearing Adult Listeners.

The Speech, Spatial, and Qualities of Hearing Scale (SSQ) and the Abbreviated Profile of Hearing Aid Benefit (APHAB) are two most commonly used questionnaires in the audiology clinic to assess an individual's self-perception of their hearing ability. Here, we present the outcomes of these two questionnaires on a large group of self-reported normal hearing adult listeners. A total of 254 self-reported normal-hearing younger and older adults completed the SSQ and the APHAB questionnaire. The younger participants completed the questionnaires through Qualtrics, whereas the older participants completed the questionnaire through Qualtrics and a traditional pen-and-paper method. The younger listeners perceived a higher ability compared to the older adults in all the SSQ subscales (Speech, Spatial, and Qualities) and reported a lesser frequency of the problems in three of the four APHAB subscales (Ease of communication, Reverberation, and Background Noise). There was no significant difference in the frequency of the problems reported in the Aversiveness subscale. Self-reported normal-hearing listeners do not rate their listening ability at the top of the ability scale. Additionally, the large dataset presented here has a potential normative value for the SSQ and the APHAB questionnaires for self-reported normal-hearing adult listeners.

Differential Effects of Binaural Pitch Fusion Range on the Benefits of Voice Gender Differences in a "Cocktail Party" Environment for Bimodal and Bilateral Cochlear Implant Users.

OBJECTIVES: Some cochlear implant (CI) users are fitted with a CI in each ear ("bilateral"), while others have a CI in one ear and a hearing aid in the other ("bimodal"). Presently, evaluation of the benefits of bilateral or bimodal CI fitting does not take into account the integration of frequency information across the ears. This study tests the hypothesis that CI listeners, especially bimodal CI users, with a more precise integration of frequency information across ears ("sharp binaural pitch fusion") will derive greater benefit from voice gender differences in a multi-talker listening environment. DESIGN: Twelve bimodal CI users and twelve bilateral CI users participated. First, binaural pitch fusion ranges were measured using the simultaneous, dichotic presentation of reference and comparison stimuli (electric pulse trains for CI ears and acoustic tones for HA ears) in opposite ears, with reference stimuli fixed and comparison stimuli varied in frequency/electrode to find the range perceived as a single sound. Direct electrical stimulation was used in implanted ears through the research interface, which allowed selective stimulation of one electrode at a time, and acoustic stimulation was used in the non-implanted ears through the headphone. Second, speech-on-speech masking performance was measured to estimate masking release by voice gender difference between target and maskers (VGRM). The VGRM was calculated as the difference in speech recognition thresholds of target sounds in the presence of same-gender or different-gender maskers. RESULTS: Voice gender differences between target and masker talkers improved speech recognition performance for the bimodal CI group, but not the bilateral CI group. The bimodal CI users who benefited the most from voice gender differences were those who had the narrowest range of acoustic frequencies that fused into a single sound with stimulation from a single electrode from the CI in the opposite ear. There was no similar voice gender difference benefit of narrow binaural fusion range for the bilateral CI users. CONCLUSIONS: The findings suggest that broad binaural fusion reduces the acoustical information available for differentiating individual talkers in bimodal CI users, but not for bilateral CI users. In addition, for bimodal CI users with narrow binaural fusion who benefit from voice gender differences, bilateral implantation could lead to a loss of that benefit and impair their ability to selectively attend to one talker in the presence of multiple competing talkers. The results suggest that binaural pitch fusion, along with an assessment of residual hearing and other factors, could be important for assessing bimodal and bilateral CI users.

A Comparison of Self-Reported Nonoccupational Noise Exposure in a Large Cohort of Listeners.

Objective: A variety of questionnaires have been developed to describe and quantify occupational and nonoccupational noise exposure, which are associated with hearing loss and tinnitus. The main aim of this study was to compare and contrast three commonly used nonoccupational noise exposure measurement questionnaires in a group of young adults. Materials and Methods: A total of 197 participants were recruited for this study. All the participants completed three commonly used nonoccupational noise exposure measurement questionnaires via Qualtrics software (Qualtrics, Provo, UT). General patterns in the nature of noise exposure were highlighted and statistical agreement and correlations between the three instruments were calculated. Comparisons were made between self-percept of noise exposure and annual noise exposure metrics obtained using questionnaires. Results: Strong statistical agreement and correlation (r = 0.57, P < 0.001) was found between the selected instruments similar in their constructs of noise exposure. When compared to quantified scores of noise exposure, self-report of exposure to loud noise was highly sensitive but associated with poor specificity (3.61%) and a high false-positive rate (96.38%). The majority of participants reported exposure to noise from listening to music and attending loud recreational activities, with a differential effect of sex on average annual noise exposure values depending on the questionnaire used. Conclusions: The outcomes of this analysis could assist in comparing noise exposure quantifications across research studies, and determining if and how these questionnaires may be utilized clinically to effectively identify and counsel those at risk for noise-induced hearing loss.

Factors underlying masking release by voice-gender differences and spatial separation cues in multi-talker listening environments in listeners with and without hearing loss.

Voice-gender differences and spatial separation are important cues for auditory object segregation. The goal of this study was to investigate the relationship of voice-gender difference benefit to the breadth of binaural pitch fusion, the perceptual integration of dichotic stimuli that evoke different pitches across ears, and the relationship of spatial separation benefit to localization acuity, the ability to identify the direction of a sound source. Twelve bilateral hearing aid (HA) users (age from 30 to 75 years) and eleven normal hearing (NH) listeners (age from 36 to 67 years) were tested in the following three experiments. First, speech-on-speech masking performance was measured as the threshold target-to-masker ratio (TMR) needed to understand a target talker in the presence of either same- or different-gender masker talkers. These target-masker gender combinations were tested with two spatial configurations (maskers co-located or 60° symmetrically spatially separated from the target) in both monaural and binaural listening conditions. Second, binaural pitch fusion range measurements were conducted using harmonic tone complexes around a 200-Hz fundamental frequency. Third, absolute localization acuity was measured using broadband (125-8000 Hz) noise and one-third octave noise bands centered at 500 and 3000 Hz. Voice-gender differences between target and maskers improved TMR thresholds for both listener groups in the binaural condition as well as both monaural (left ear and right ear) conditions, with greater benefit in co-located than spatially separated conditions. Voice-gender difference benefit was correlated with the breadth of binaural pitch fusion in the binaural condition, but not the monaural conditions, ruling out a role of monaural abilities in the relationship between binaural fusion and voice-gender difference benefits. Spatial separation benefit was not significantly correlated with absolute localization acuity. In addition, greater spatial separation benefit was observed in NH listeners than in bilateral HA users, indicating a decreased ability of HA users to benefit from spatial release from masking (SRM). These findings suggest that sharp binaural pitch fusion may be important for maximal speech perception in multi-talker environments for both NH listeners and bilateral HA users.

Effect of gap detection threshold and localisation acuity on spatial release from masking in older adults.

OBJECTIVE: The primary objective of this experiment was to measure the temporal and spatial processing capabilities of older individuals and use statistical models to identify the individual contributions of these temporal and spatial processing capabilities to spatial release from masking (SRM). DESIGN: Repeated measures. STUDY SAMPLE: Twenty-five older listeners with varying degrees of hearing loss participated in this experiment. SRM using the coordinate response measure, gap detection thresholds and localisation acuity for 1/3-octave-wide Gaussian noise bands centred at 500 and 4000 Hz were measured for all the listeners. RESULTS: Older listeners had better speech recognition thresholds when target and maskers were spatially separated as compared to when they were co-located. In addition, hearing loss and localisation acuity at 500 Hz were significant predictors in a multiple regression model predicting SRM. However, gap detection thresholds did not significantly contribute to the multiple regression model predicting SRM. CONCLUSION: Based on our data, we conclude that SRM at 30° spatial separation between the target and symmetric maskers is driven by the ability of the individuals to use interaural time difference cues.

Impacts of Diabetes, Aging, and Hearing Loss on Speech-on-Speech Masking and Spatial Release in a Large Veteran Cohort.

PURPOSE: Type 2 diabetes mellitus (DM2) is associated with impaired hearing. However, the evidence is less clear if DM2 can lead to difficulty understanding speech in complex acoustic environments, independently of age and hearing loss effects. The purpose of this study was to estimate the magnitude of DM2-related effects on speech understanding in the presence of competing speech after adjusting for age and hearing. METHOD: A cross-sectional study design was used to investigate the relationship between DM2 and speech understanding in 190 Veterans (M age = 47 years, range: 25-76). Participants were classified as having no diabetes (n = 74), prediabetes (n = 19), or DM2 that was well controlled (n = 24) or poorly controlled (n = 73). A test of spatial release from masking (SRM) was presented in a virtual acoustical simulation over insert earphones with multiple talkers using sentences from the coordinate response measure corpus to determine the target-to-masker ratio (TMR) required for 50% correct identification of target speech. A linear mixed model of the TMR results was used to estimate SRM and separate effects of diabetes group, age, and low-frequency pure-tone average (PTA-low) and high-frequency pure-tone average. A separate model estimated the effects of DM2 on PTA-low. RESULTS: After adjusting for hearing and age, diabetes-related effects remained among those whose DM2 was well controlled, showing an SRM loss of approximately 0.5 dB. Results also showed effects of hearing loss and age, consistent with the literature on people without DM2. Low-frequency hearing loss was greater among those with DM2. CONCLUSIONS: In a large cohort of Veterans, low-frequency hearing loss and older age negatively impact speech understanding. Compared with nondiabetics, individuals with controlled DM2 have additional auditory deficits beyond those associated with hearing loss or aging. These results provide a potential explanation for why individuals who have diabetes and/or are older often report difficulty understanding speech in real-world listening environments. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.16746475.

Comparing Spatial Release From Masking Using Traditional Methods and Portable Automated Rapid Testing iPad App.

Purpose The purpose of this study was to compare speech identification abilities of individuals of various ages and hearing abilities using traditional methods and Portable Automated Rapid Testing (PART) iPad app. Method Speech identification data were collected using three techniques: over headphones using a virtual speaker array, using PART iPad app (UCR Brain Game Center, 2018), and using loudspeaker presentation in a sound-attenuated room. For all three techniques, Coordinate Response Measure sentences were used as the stimuli and "Charlie" was used as the call sign. A progressive tracking procedure was used to estimate the speech identification thresholds for listeners with varying hearing thresholds. The target sentence was always presented at 0° azimuth angle, whereas the maskers were colocated (0°) with the target or symmetrically spatially separated by ±15°, ±30°, or ±45°. Results Data analysis revealed similar speech identification thresholds for the iPad and headphone conditions and slightly poorer thresholds for the loudspeaker array condition across participant groups. This was true for all spatial separations between the target and the maskers. Conclusion Strong correlation between the headphone and iPad data presented in this study indicated that the spatial release from masking module in the PART iPad app can be used as a clinical tool to assess spatial processing ability prior to audiologic evaluation in the clinic and can also be used to make recommendations for and to track progress with aural rehabilitation programs over time.

Pilot Comparison of Adjustment Protocols of Personal Sound Amplification Products.

The Over-the-Counter Hearing Aid Act of 2017 was signed into law in August 2017 and facilitates the introduction of direct-to-consumer sales of hearing aids for adults with mild-to-moderate hearing loss. Among many questions surrounding over-the-counter sales is the ability of users to self-fit amplification. Many studies have conducted self-fitting procedures using guidance materials provided by audiologists. In this pilot, we explore the ability of users to self-adjust personal sound amplification devices using only materials provided by the manufacturer and contrast this with models that involve a hearing professional. Outcomes to assess adjustments included clinic-based speech-in-noise measures and ability to approximate NAL-NL2 prescriptive targets. We found that an audiologist-driven model provided the best outcomes. However, it is unknown if the difference is clinically meaningful.

Development and validation of Portable Automated Rapid Testing (PART) measures for auditory research.

The current state of consumer-grade electronics means that researchers, clinicians, students, and members of the general public across the globe can create high-quality auditory stimuli using tablet computers, built-in sound hardware, and calibrated consumer-grade headphones. Our laboratories have created a free application that supports this work: PART (Portable Automated Rapid Testing). PART has implemented a range of psychoacoustical tasks including: spatial release from speech-on-speech masking, binaural sensitivity, gap discrimination, temporal modulation, spectral modulation, and spectrotemporal modulation (STM). Here, data from the spatial release and STM tasks are presented. Data were collected across the globe on tablet computers using applications available for free download, built-in sound hardware, and calibrated consumer-grade headphones. Spatial release results were as good or better than those obtained with standard laboratory methods. Spectrotemporal modulation thresholds were obtained rapidly and, for younger normal hearing listeners, were also as good or better than those in the literature. For older hearing impaired listeners, rapid testing resulted in similar thresholds to those reported in the literature. Listeners at five different testing sites produced very similar STM thresholds, despite a variety of testing conditions and calibration routines. Download Spatial Release, PART, and Listen: An Auditory Training Experience for free at https://bgc.ucr.edu/games/.

The role of early and late reflections on spatial release from masking: Effects of age and hearing loss.

Early reflections have been linked to improved speech intelligibility, while later-arriving reverberant sound has been shown to limit speech understanding. Here, these effects were examined by artificially removing either early reflections or late reflections. Removing late reflections improved performance more for colocated than for spatially separated maskers. Results of a multiple regression analysis suggest that pure-tone average (PTA) is a significant predictor of spatial release from masking (SRM) in all acoustic conditions. Controlling for the effects of PTA, age is a significant predictor of SRM only when early reflections are absent.

Release from masking for small spatial separations: Effects of age and hearing loss.

Spatially separating target and masking speech can result in substantial spatial release from masking (SRM) for normal-hearing listeners. In this study, SRM was examined at eight spatial configurations of azimuth angle: maskers co-located with the target (0°) or symmetrically separated by 2°, 4°, 6°, 8°, 10°, 15°, or 30°. Results revealed that different listening groups (young normal-hearing, older normal-hearing, and older hearing-impaired) required different minimum amounts of spatial separation between target and maskers to achieve SRM. The results also indicated that aging was the contributing factor predicting SRM at smaller separations, whereas hearing loss was the contributing factor at larger separations.

Prior exposure to a reverberant listening environment improves speech intelligibility in adult cochlear implant listeners.

OBJECTIVES: The goal of this study is to investigate whether prior exposure to reverberant listening environment improves speech intelligibility of adult cochlear implant (CI) users. METHODS: Six adult CI users participated in this study. Speech intelligibility was measured in five different simulated reverberant listening environments with two different speech corpuses. Within each listening environment, prior exposure was varied by either having the same environment across all trials (blocked presentation) or having different environment from trial to trial (unblocked). RESULTS: Speech intelligibility decreased as reverberation time increased. Although substantial individual variability was observed, all CI listeners showed an increase in the blocked presentation condition as compared to the unblocked presentation condition for both speech corpuses. CONCLUSION: Prior listening exposure to a reverberant listening environment improves speech intelligibility in adult CI listeners. Further research is required to understand the underlying mechanism of adaptation to listening environment.

Effects of Reverberation and Compression on Consonant Identification in Individuals with Hearing Impairment.

OBJECTIVES: Hearing aids are frequently used in reverberant environments; however, relatively little is known about how reverberation affects the processing of signals by modern hearing-aid algorithms. The purpose of this study was to investigate the acoustic and behavioral effects of reverberation and wide-dynamic range compression (WDRC) in hearing aids on consonant identification for individuals with hearing impairment. DESIGN: Twenty-three listeners with mild to moderate sloping sensorineural hearing loss were tested monaurally under varying degrees of reverberation and WDRC conditions. Listeners identified consonants embedded within vowel-consonant-vowel nonsense syllables. Stimuli were processed to simulate a range of realistic reverberation times and WDRC release times using virtual acoustic simulations. In addition, the effects of these processing conditions were acoustically analyzed using a model of envelope distortion to examine the effects on the temporal envelope. RESULTS: Aided consonant identification significantly decreased as reverberation time increased. Consonant identification was also significantly affected by WDRC release time. This relationship was such that individuals tended to perform significantly better with longer release times. There was no significant interaction between reverberation and WDRC. The application of the acoustic model to the processed signal showed a close relationship between trends in the behavioral performance and distortion to the temporal envelope resulting from reverberation and WDRC. The results of the acoustic model demonstrated the same trends found in the behavioral data for both reverberation and WDRC. CONCLUSIONS: Reverberation and WDRC release time both affect aided consonant identification for individuals with hearing impairment, and these condition effects are associated with alterations to the temporal envelope. There was no significant interaction between reverberation and WDRC release time.

Enhancement of speech intelligibility in reverberant rooms: role of amplitude envelope and temporal fine structure.

The temporal envelope and fine structure of speech make distinct contributions to the perception of speech in normal-hearing listeners, and are differentially affected by room reverberation. Previous work has demonstrated enhanced speech intelligibility in reverberant rooms when prior exposure to the room was provided. Here, the relative contributions of envelope and fine structure cues to this intelligibility enhancement were tested using an open-set speech corpus and virtual auditory space techniques to independently manipulate the speech cues within a simulated room. Intelligibility enhancement was observed only when the envelope was reverberant, indicating that the enhancement is envelope-based.

Prior listening exposure to a reverberant room improves open-set intelligibility of high-variability sentences.

Previous studies have demonstrated that speech understanding in reverberant rooms improves when listeners are given prior exposure to the room. Results from these room-adaptation studies are limited, however, because they were conducted with materials that are not representative of the high acoustic variability observed in speech signals during everyday communication. Here, room adaptation effects were measured using an open-set speech corpus with high lexical and indexical variability and virtual auditory space techniques to simulate binaural listening in rooms. Room adaptation effects of comparable magnitude to previous studies were observed, suggesting general importance for facilitating speech intelligibility in reverberation.

Phonemic restoration effect reversed in a reverberant room.

Classic demonstrations of the phonemic restoration effect show increased intelligibility of interrupted speech when the interruptions are caused by a plausible masking sound rather than by silent periods. Previous studies of this effect have been conducted exclusively under anechoic or nearly anechoic listening conditions. This study demonstrates that the effect is reversed when sounds are presented in a realistically simulated reverberant room (broadband T(60) = 1.1 s): intelligibility is greater for silent interruptions than for interruptions by unmodulated noise. Additional results suggest that the reversal is primarily due to filling silent intervals with reverberant energy from the speech signal.

Amplitude modulation detection by human listeners in reverberant sound fields: Carrier bandwidth effects and binaural versus monaural comparison.

Previous work [Zahorik et al., POMA, 12, 050005 (2011)] has reported that for a broadband noise carrier signal in a simulated reverberant sound field, human sensitivity to amplitude modulation (AM) is higher than would be predicted based on the broadband acoustical modulation transfer function (MTF) of the listening environment. Interpretation of this result was complicated by the fact that acoustical MTFs of rooms are often quite different for different carrier frequency regions, and listeners may have selectively responded to advantageous carrier frequency regions where the effective acoustic modulation loss due to the room was less than indicated by a broadband acoustic MTF analysis. Here, AM sensitivity testing and acoustic MTF analyses were expanded to include narrowband noise carriers (1-octave and 1/3-octave bands centered at 4 kHz), as well as monaural and binaural listening conditions. Narrowband results were found to be consistent with broadband results: In a reverberant sound field, human AM sensitivity is higher than indicated by the acoustical MTFs. The effect was greatest for modulation frequencies above 32 Hz and was present whether the stimulation was monaural or binaural. These results are suggestive of mechanisms that functionally enhance modulation in reverberant listening.