Speech Recognition In Noise Research Articles

Listen up! ADHD slows spoken-word processing in adverse listening conditions: Evidence from eye movements

BackgroundCognitive skills such as sustained attention, inhibition and working memory are essential for speech processing, yet are often impaired in people with ADHD. Offline measures have indicated difficulties in speech recognition on multi-talker babble (MTB) background for young adults with ADHD (yaADHD). However, to-date no study has directly tested online speech processing in adverse conditions for yaADHD. AimsGauging the effects of ADHD on segregating the spoken target-word from its sound-sharing competitor, in MTB and working-memory (WM) load. Methods and proceduresTwenty-four yaADHD and 22 matched controls that differ in sustained attention (SA) but not in WM were asked to follow spoken instructions presented on MTB to touch a named object, while retaining one (low-load) or four (high-load) digit/s for later recall. Their eye fixations were tracked. Outcomes and resultsIn the high-load condition, speech processing was less accurate and slowed by 140ms for yaADHD. In the low-load condition, the processing advantage shifted from early perceptual to later cognitive stages. Fixation transitions (hesitations) were inflated for yaADHD. Conclusions and implicationsADHD slows speech processing in adverse listening conditions and increases hesitation, as speech unfolds in time. These effects, detected only by online eyetracking, relate to attentional difficulties. We suggest online speech processing as a novel purview on ADHD. What this paper adds?We suggest speech processing in adverse listening conditions as a novel vantage point on ADHD. Successful speech recognition in noise is essential for performance across daily settings: academic, employment and social interactions. It involves several executive functions, such as inhibition and sustained attention. Impaired performance in these functions is characteristic of ADHD. However, to date there is only scant research on speech processing in ADHD. The current study is the first to investigate online speech processing as the word unfolds in time using eyetracking for young adults with ADHD (yaADHD). This method uncovered slower speech processing in multi-talker babble noise for yaADHD compared to matched controls. The performance of yaADHD indicated increased hesitation between the spoken word and sound-sharing alternatives (e.g., CANdle-CANdy). These delays and hesitations, on the single word level, could accumulate in continuous speech to significantly impair communication in ADHD, with severe implications on their quality of life and academic success. Interestingly, whereas yaADHD and controls were matched on WM standardized tests, WM load appears to affect speech processing for yaADHD more than for controls. This suggests that ADHD may lead to inefficient deployment of WM resources that may not be detected when WM is tested alone. Note that these intricate differences could not be detected using traditional offline accuracy measures, further supporting the use of eyetracking in speech tasks. Finally, communication is vital for active living and wellbeing. We suggest paying attention to speech processing in ADHD in treatment and when considering accessibility and inclusion.

Hearing Loss and Cognitive Function in Early Old Age: Comparing Subjective and Objective Hearing Measures

Introduction: Population-based research has consistently shown that people with hearing loss are at greater risk of cognitive impairment. We aimed to explore the cross-sectional association of both subjective and objective hearing measures with global and domain-specific cognitive function. We also examined the influence of hearing aid use on the relationship. Methods: A population-based sample (n = 1,105, 52% women) of 70-year-olds that were representative of the inhabitants of the city of Gothenburg, Sweden completed a detailed cognitive examination, pure-tone audiometry, and a questionnaire regarding perceived hearing problems. A subsample (n = 247, 52% women) also completed a test of speech-recognition-in-noise (SPRIN). Multiple linear regression analyses were conducted to explore the association of hearing with cognitive function, adjusting for sex, education, cardiovascular factors, and tinnitus. Results: Global cognitive function was independently associated with the better ear pure-tone average across 0.5–4 kHz (PTA4, β = −0.13, 95% CI, −0.18, −0.07), the better ear SPRIN score (β = 0.30, 95% CI, 0.19, 0.40), but not with the self-reported hearing measure (β = −0.02, 95% CI, −0.07, 0.03). Both verbally loaded and nonverbally loaded tasks, testing a variety of cognitive domains, contributed to the association. Hearing aid users had better global cognitive function than nonusers with equivalent hearing ability. The difference was only significant in the mild hearing loss category. Discussion: In a population-based sample of 70-year-old persons without dementia, poorer hearing was associated with poorer global and domain-specific cognitive function, but only when hearing function was measured objectively and not when self-reported. The speech-in-noise measure showed the strongest association. This highlights the importance of including standardized hearing tests and controlling for hearing status in epidemiological geriatric research. More research is needed on the role that hearing aid use plays in relation to age-related cognitive declines.

User characteristics associated with use of wrist-worn wearables and physical activity apps by adults with and without impaired speech-in-noise recognition: a cross-sectional analysis

Objective To study weekly use of smartwatches, fitness watches and physical activity apps among adults with and without impaired speech-in-noise (SIN) recognition, to identify subgroups of users. Design Cross-sectional study. Study sample Adults (aged 28–80 years) with impaired (n = 384) and normal SIN recognition (n = 341) as measured with a web-based digits-in-noise test, from the Netherlands Longitudinal Study on Hearing. Multiple logistic regression analyses were used to study differences and to build an association model. Results Employed adults in both groups are more likely to use each type of fitness technology (all ORs >3.4, all p-values < 0.004). Specific to fitness watch use, adults living with others use it more (OR 2.5, 95%CI 1.1;5.8, p = 0.033) whereas those abstaining from alcohol (OR 0.3, 95%CI 0.1;0.6) or consuming >2 glasses/week (OR 0.4, 95%CI 0.2;0.81, overall p = 0.006) and hearing aid users (OR 0.5, 95%CI 0.2;0.9, p = 0.024) make less use. Conclusions Subgroups of adults more and less likely to use fitness technology exist, but do not differ between adults with and without impaired SIN recognition. More research is needed to confirm these results and to develop interventions to increase physical activity levels among adults with hearing loss.

Informational Masking and Listening Effort in Speech Recognition in Noise: The Role of Working Memory Capacity and Inhibitory Control in Older Adults With and Without Hearing Impairment.

The study aimed to assess the relationship between (a) speech recognition in noise, mask type, working memory capacity (WMC), and inhibitory control and (b) self-rated listening effort, speech material, and mask type, in older adults with and without hearing impairment. It was of special interest to assess the relationship between WMC, inhibitory control, and speech recognition in noise when informational maskers masked target speech. A mixed design was used. A group (N = 24) of older (Mage = 69.7 years) individuals with hearing impairment and a group of age normal-hearing adults (Mage = 59.3 years, SD = 6.5) participated in the study. The participants were presented with auditory tests in a sound-attenuated room and with cognitive tests in a quiet office. The participants were asked to rate listening effort after being presented with energetic and informational background maskers in two different speech materials used in this study (i.e., Hearing In Noise Test and Hagerman test). Linear mixed-effects models were set up to assess the effect of the two different speech materials, energetic and informational maskers, hearing ability, WMC, inhibitory control, and self-rated listening effort. Results showed that WMC and inhibitory control were of importance for speech recognition in noise, even when controlling for pure-tone average 4 hearing thresholds and age, when the maskers were informational. Concerning listening effort, on the other hand, the results suggest that hearing ability, but not cognitive abilities, is important for self-rated listening effort in speech recognition in noise. Speech-in-noise recognition is more dependent on WMC for older adults in informational maskers than in energetic maskers. Hearing ability is a stronger predictor than cognition for self-rated listening effort. https://doi.org/10.23641/asha.21357648.

Genetic Hearing Loss Affects Cochlear Processing.

The relationship between speech recognition and hereditary hearing loss is not straightforward. Underlying genetic defects might determine an impaired cochlear processing of sound. We obtained data from nine groups of patients with a specific type of genetic hearing loss. For each group, the affected cochlear site-of-lesion was determined based on previously published animal studies. Retrospectively obtained speech recognition scores in noise were related to several aspects of supra-threshold cochlear processing as assessed by psychophysical measurements. The differences in speech perception in noise between these patient groups could be explained by these factors and partially by the hypothesized affected structure of the cochlea, suggesting that speech recognition in noise was associated with a genetics-related malfunctioning of the cochlea. In particular, regression models indicate that loudness growth and spectral resolution best describe the cochlear distortions and are thus a good biomarker for speech understanding in noise.

Effect of Combining Sound Therapy with Pharmacotherapy on the Recovery of Hearing Abilities in the Case of Sudden Sensorineural Hearing Loss: A Prospective Study.

This study investigated the effect of sound therapy combined with drug therapy (SDT) on gap detection threshold and speech recognition scores in patients with sudden sensorineural hearing loss (SSNHL). Patients with SSNHL were grouped randomly into SDT and drug therapy (DT) groups. All patients received standard drug treatment and patients in the SDT group additionally received sound stimulation for the affected ears for 6days. Pure tone audiogram, speech recognition scores at normal and time-compressed rates under quiet and noisy conditions, and the gap detection threshold of the SDT and DT groups before treatment and on day6 and 30 after treatment were compared. There were 20 patients in the SDT group and 24 in the DT group. The pure tone thresholds of affected ears were significantly lower in the SDT group on day6 after treatment than those in the DT group at 125 and 250Hz. Significantly lower gap detection thresholds and higher speech recognition scores under noisy conditions were observed at the normal and time-compressed rates in the SDT group than those in the DT group on day6 and 30 after treatment. Significant correlations were observed between the gap thresholds and speech recognition scores in a noisy environment at normal and time-compressed rates on day6 and 30. SDT may improve the recovery of hearing abilities, such as the gap in noise thresholds and speech recognition in noise, in the case of SSNHL. ChiCTR-IOR-17012262.

Afferent Loss, GABA, and Central Gain in Older Adults: Associations with Speech Recognition in Noise.

Deficits in auditory nerve (AN) function for older adults reduce afferent input to the cortex. The extent to which the cortex in older adults adapts to this loss of afferent input and the mechanisms underlying this adaptation are not well understood. We took a neural systems approach measuring AN and cortical evoked responses within 50 older and 27 younger human adults (59 female) to estimate central gain or increased cortical activity despite reduced AN activity. Relative to younger adults, older adults' AN response amplitudes were smaller, but cortical responses were not. We used the relationship between AN and cortical response amplitudes in younger adults to predict cortical response amplitudes for older adults from their AN responses. Central gain in older adults was thus defined as the difference between their observed cortical responses and those predicted from the parameter estimates of younger adults. In older adults, decreased afferent input contributed to lower cortical GABA levels, greater central gain, and poorer speech recognition in noise (SIN). These effects on SIN occur in addition to, and independent from, effects attributed to elevated hearing thresholds. Our results are consistent with animal models of central gain and suggest that reduced AN afferent input in some older adults may result in changes in cortical encoding and inhibitory neurotransmission, which contribute to reduced SIN. An advancement in our understanding of the changes that occur throughout the auditory system in response to the gradual loss of input with increasing age may provide potential therapeutic targets for intervention.SIGNIFICANCE STATEMENT Age-related hearing loss is one of the most common chronic conditions of aging, yet little is known about how the cortex adapts to this loss of sensory input. We measured AN and cortical responses to the same stimulus in younger and older adults. In older adults we found hyperexcitability in cortical activity relative to concomitant declines in afferent input that are consistent with central gain. Lower levels of cortical GABA, an inhibitory neurotransmitter, were associated with greater central gain, which predicted poorer SIN. The results suggest that the cortex in older adults may adapt to attenuated sensory input by reducing inhibition to amplify the cortical response, but this amplification may lead to poorer SIN.

Increased rate of listening difficulties in autistic children

IntroductionAuditory challenges are both common and disruptive for autistic children and evidence suggests that listening difficulties may be linked to academic underachievement (Ashburner, Ziviani & Rodger, 2008). Such deficits may also contribute to issues with attention, behavior, and communication (Ashburner et al., 2008; Riccio, Cohen, Garrison & Smith, 2005). The present study aims to summarize the auditory challenges of autistic children with normal pure-tone hearing thresholds, and perceived listening difficulties, seen at auditory-ASD clinics in the US and Australia. MethodsData were compiled on a comprehensive, auditory-focused test battery in a large clinical sample of school-age autistic children with normal pure-tone hearing to date (N = 71, 6–14 years). Measures included a parent-reported auditory sensory processing questionnaire and tests of speech recognition in noise, binaural integration, attention, auditory memory and listening comprehension. Individual test performance was compared to normative data from children with no listening difficulties. ResultsOver 40% of patients exhibited significantly reduced speech recognition in noise and abnormal dichotic integration that were not attributed to deficits in attention. The majority of patients (86%) performed abnormally on at least one auditory measure, suggesting that functional auditory issues can exist in autistic patients despite normal pure-tone sensitivity. ConclusionIncluding functional listening measures during audiological evaluations may improve clinicians’ ability to detect and manage the auditory challenges impacting this population. Learner Outcomes: 1) Readers will be able to describe the auditory difficulties experienced by some autistic patients (ASD). 2) Readers will be able to describe clinical measures potentially useful for detecting listening difficulties in high-functioning autistic children.

Effect of Age on Informational Masking: Differential Effects of Phonetic and Semantic Information in the Masker.

Speech recognition in noise is a ubiquitous problem in older listeners. Speech, the most commonly encountered noise in the real world, causes greater masking than noise maskers, a phenomenon called informational masking (IM). This is due to the lexical-semantic and/or acoustic-phonetic information present in speech maskers. In this study, we aimed to observe the age-related differences in speech recognition and the magnitudes of IM when the maskers varied in the type of linguistic information. In 30 young and 30 older individuals, we measured the signal-to-noise ratio required to obtain 50% correct identification under four-talker babble (lexical-semantic and acoustic-phonetic information), four-talker reverse babble (predominantly acoustic-phonetic information), and speech-shaped noise (SSN; energetic). In both groups, the four-talker babble caused the greatest masking effect (worst performances), whereas the SSN resulted in the least masking effect (best performances). The effectiveness of IM due to the lexical-semantic information was comparable between the two groups. However, the effectiveness of IM due to the acoustic-phonetic information was significantly higher in the older listeners, causing worse performances. The greater effectiveness of IM due to the acoustic-phonetic information (worse performance) could be due to the minimal-to-mild high-frequency hearing loss and the consequent temporal processing deficits observed in the older listeners. However, it is possible that the older listeners can employ compensatory mechanisms (such as life experiences, contextual cues, employing higher listening efforts, among many possible other mechanisms) to overcome some of these deficits. https://doi.org/10.23641/asha.20405730.

Compensation effect of hearing aid on speech recognition in noise in patients with unilateral hearing loss

Objective:The aim of this study was to investigate the speech recognition in noise in patients with unilateral hearing loss（UHL）, and explore the compensation effect of behind-the-ear（BTE） hearing aid on speech recognition in patients with varied degrees of UHL. Methods:Twenty-five participants with UHL were divided into two groups according to the degree of hearing loss: one group included subjects with unilateral moderate and moderately severe hearing loss and another one included subjects with unilateral severe and profound hearing loss. Fifteen healthy subjects with normal hearing were enrolled as the control group. The speech recognition thresholds and speech recognition scores at fixed signal noise ratio（SNR） in UHL participants with and without BTE hearing aid were tested in the sound field and compared with those in the control group. One-way ANOVA was used to examine the significance of the difference between UHL participants and control group, and paired t-test was used to analyze the compensation effect of hearing aid on speech recognition in noise in UHL participants. Results:The speech recognition thresholds were significantly higher in both UHL groups（P<0.01） compared with the control group, there was no significant difference between two UHL groups. And the speech recognition scores were significantly lower when the SNR was fixed（P<0.01）, and there were no significant differences between two UHL groups. When fitting BTE hearing aid, the speech recognition thresholds of the two groups significantly decreased（P<0.01）, and the speech recognition scores significantly improved（P<0.01）. Conclusion:Patients with above moderate UHL presented a significant decrease in performance of speech recognition in noise, and fitting BTE hearing aid on the affected ear had a positive compensation effect.

Masked Speech Recognition as a Function of Masker Location for Cochlear Implant Users With Single-Sided Deafness.

Cochlear implant (CI) recipients with normal or near normal hearing (NH) in the contralateral ear, referred to as single-sided deafness (SSD), experience significantly better speech recognition in noise with their CI than without it, although reported outcomes vary. One possible explanation for differences in outcomes across studies could be differences in the spatial configurations used to assess performance. This study compared speech recognition for different spatial configurations of the target and masker, with test materials used clinically. Sixteen CI users with SSD completed tasks of masked speech recognition presented in five spatial configurations. The target speech was presented from the front speaker (0° azimuth). The masker was located either 90° or 45° toward the CI-ear or NH-ear or colocated with the target. Materials were the AzBio sentences in a 10-talker masker and the Bamford-Kowal-Bench Speech-in-Noise test (BKB-SIN; four-talker masker). Spatial release from masking (SRM) was computed as the benefit associated with spatial separation relative to the colocated condition. Performance was significantly better when the masker was separated toward the CI-ear as compared to colocated. No benefit was observed for spatial separations toward the NH-ear. The magnitude of SRM for spatial separations toward the CI-ear was similar for 45° and 90° when tested with the AzBio sentences, but a larger benefit was observed for 90° as compared to 45° for the BKB-SIN. Masked speech recognition in CI users with SSD varies as a function of the spatial configuration of the target and masker. Results supported an expansion of the clinical test battery at the study site to assess binaural hearing abilities for CI candidates and recipients with SSD. The revised test battery presents the target from the front speaker and the masker colocated with the target, 90° toward the CI-ear, or 90° toward the NH-ear.

The Relationship between Speech Perception in Quiet and in Noise for Young Adults with Pure-Tone Thresholds ≤ 25 dB HL.

The standard audiological protocol utilizes quiet measures. However, it has been noted that speech recognition in noise (SRN) testing provides information that cannot be inferred from quiet measures. The purpose of this convergent validity study was to investigate the relationships between behavioral responses in quiet and in noise. Bilateral pure-tone averages (BPTA) were calculated for thresholds from 500 to 6000 Hz. The Hearing in Noise Test (HINT) thresholds in quiet (HINT-Q) were also measured. SRN performances were determined using the HINT Noise Front (HINT-F) condition and the AzBio test. The HINT-F uses steady-state speech-shaped noise and the AzBio uses a 10-talker babble. All conditions were randomized. Fifty young, native English-speaking females with pure-tone thresholds less than or equal to 25 dB HL participated in this study. The average age of the participants was 20.5 years (standard deviation = 1.47). Pearson correlation coefficients were used to quantify the relationships between all measures. Statistically significant relationships were found between HINT-Q thresholds versus BPTA (0.5-6.0 kHz) (r = 0.62, p < 0.01) and between HINT-F thresholds versus AzBio (0 dB signal-to-noise ratio) scores (r = -0.41, p < 0.05). No significant relationships were found between any of the quiet versus noise measures. These results suggest that, for individuals with pure-tone thresholds less than or equal to 25 dB HL, SRN ability must be measured directly and not inferred from PTA or speech-in-quiet measures. It is possible, to a modest degree, to predict AzBio performances from the HINT-F thresholds, and vice versa.

Celebrating the one millionth cochlear implant

Cochlear implants have been the most successful neural prosthesis, with one million users globally. Researchers used the source-filter model and speech vocoder to design the modern multi-channel implants, allowing implantees to achieve 70%-80% correct sentence recognition in quiet, on average. Researchers also used the cochlear implant to help understand basic mechanisms underlying loudness, pitch, and cortical plasticity. While front-end processing advances improved speech recognition in noise, the unilateral implant speech recognition in quiet has plateaued since the early 1990s. This lack of progress calls for action on re-designing the cochlear stimulating interface and collaboration with the general neurotechnology community.

Remote-Microphone Benefit in Noise and Reverberation for Children Who are Hard of Hearing.

Remote-microphone (RM) systems are designed to reduce the impact of poor acoustics on speech understanding. However, there is limited research examining the effects of adding reverberation to noise on speech understanding when using hearing aids (HAs) and RM systems. Given the significant challenges posed by environments with poor acoustics for children who are hard of hearing, we evaluated the ability of a novel RM system to address the effects of noise and reverberation. We assessed the effect of a recently developed RM system on aided speech perception of children who were hard of hearing in noise and reverberation and how their performance compared to peers who are not hard of hearing (i.e., who have hearing thresholds no greater than 15 dB HL). The effect of aided speech audibility on sentence recognition when using an RM system also was assessed. Twenty-two children with mild to severe hearing loss and 17 children who were not hard of hearing (i.e., with hearing thresholds no greater than 15 dB HL) (7-18 years) participated. An adaptive procedure was used to determine the signal-to-noise ratio for 50 and 95% correct sentence recognition in noise and noise plus reverberation (RT 300 ms). Linear mixed models were used to examine the effect of listening conditions on speech recognition with RMs for both groups of children and the effects of aided audibility on performance across all listening conditions for children who were hard of hearing. Children who were hard of hearing had poorer speech recognition for HAs alone than for HAs plus RM. Regardless of hearing status, children had poorer speech recognition in noise plus reverberation than in noise alone. Children who were hard of hearing had poorer speech recognition than peers with thresholds no greater than 15 dB HL when using HAs alone but comparable or better speech recognition with HAs plus RM. Children with better-aided audibility with the HAs showed better speech recognition with the HAs alone and with HAs plus RM. Providing HAs that maximize speech audibility and coupling them with RM systems has the potential to improve communication access and outcomes for children who are hard of hearing in environments with noise and reverberation.

Evaluating the Effectiveness of a New Auditory Training Program on the Speech Recognition Skills and Auditory Event-Related Potentials in Elderly Hearing Aid Users

Introduction: The objective of this study was to evaluate the effectiveness of a new auditory training (AT) program on the speech recognition in the noise and on the auditory event-related potentials in elderly hearing aid users. Methods: Thirty-three elderly individuals using hearing aids aged from 60 to 80 years participated. A new AT program was developed for the study. AT program lasts for 8 weeks and includes sound discrimination exercises and cognitive exercises. Seventeen individuals (mean age 72.17 ± 6.94) received AT and 16 individuals (mean age 71.75 ± 6.81) did not receive AT. The mismatch negativity (MMN) test and matrix test were used to evaluate the effectiveness of AT. Tests were conducted for the study group before and after the AT. The tests were carried out for the control group at the same times with the study group and the results were compared. Results: In comparison with the first evaluation, the last evaluation of the study group demonstrated a significant difference regarding the decrease of mean latency in the MMN wave (p = 0.038), and regarding the improving score of matrix test (p = 0.004), there was no difference in the control group. Conclusion: The AT program prepared for the study was effective in improving speech recognition in noise in the elderly, and the efficiency of AT could be demonstrated with MMN and matrix test.

Pediatric speech understanding in noise and the role of working memory andcomprehension

Working memory is vital to a child’s cognitive processing and speech understanding in noise. More recent findings suggest that the relationship between speech recognition in noise and auditory comprehension may be capturing difficulties in understanding speech in noise which have been linked to cognitive and linguistic skills. Children’s auditory-cognitive performance is highly sensitive to processing load. The extent that children engage cognitive resources depends on demands of task difficulty and intensity level of four-talker babble. The combined costs of performing a difficult task in adverse acoustical conditions are greater than the sum of the individual costs. This suggest that the relationship between speech recognition in noise and auditory comprehension may be capturing difficulties in language which may have effects in academic success. Data will be presented (1) show that audibility alone does not account for difficulties in speech perception in noise (2) showing the complex relationship between working memory and auditory comprehension. (3) Implications for clinical speech in noise screener for children. While app-based interventions for speech and language exist, to our knowledge, none explicitly screen for perception of speech in the presence of noise.

Relationships between behavioural and self-report measures in speech recognition in noise

Objective Using data from the n200-study, we aimed to investigate the relationship between behavioural (the Swedish HINT and Hagerman speech-in-noise tests) and self-report (Speech, Spatial and Qualities of Hearing Questionnaire (SSQ)) measures of listening under adverse conditions. Design The Swedish HINT was masked with a speech-shaped noise (SSN), the Hagerman was masked with a SSN and a four-talker babble, and the subscales from the SSQ were used as a self-report measure. The HINT and Hagerman were administered through an experimental hearing aid. Study sample This study included 191 hearing aid users with hearing loss (mean PTA4 = 37.6, SD = 10.8) and 195 normally hearing adults (mean PTA4 = 10.0, SD = 6.0). Results The present study found correlations between behavioural measures of speech-in-noise and self-report scores of the SSQ in normally hearing individuals, but not in hearing aid users. Conclusion The present study may help identify relationships between clinically used behavioural measures, and a self-report measure of speech recognition. The results from the present study suggest that use of a self-report measure as a complement to behavioural speech in noise tests might help to further our understanding of how self-report, and behavioural results can be generalised to everyday functioning.

Do Age and Linguistic Status Alter the Effect of Sound Source Diffuseness on Speech Recognition in Noise?

One aspect of auditory scenes that has received very little attention is the level of diffuseness of sound sources. This aspect has increasing importance due to growing use of amplification systems. When an auditory stimulus is amplified and presented over multiple, spatially-separated loudspeakers, the signal’s timbre is altered due to comb filtering. In a previous study we examined how increasing the diffuseness of the sound sources might affect listeners’ ability to recognize speech presented in different types of background noise. Listeners performed similarly when both the target and the masker were presented via a similar number of loudspeakers. However, performance improved when the target was presented using a single speaker (compact) and the masker from three spatially separate speakers (diffuse) but worsened when the target was diffuse, and the masker was compact. In the current study, we extended our research to examine whether the effects of timbre changes with age and linguistic experience. Twenty-four older adults whose first language was English (Old-EFLs) and 24 younger adults whose second language was English (Young-ESLs) were asked to repeat non-sense sentences masked by either Noise, Babble, or Speech and their results were compared with those of the Young-EFLs previously tested. Participants were divided into two experimental groups: (1) A Compact-Target group where the target sentences were presented over a single loudspeaker, while the masker was either presented over three loudspeakers or over a single loudspeaker; (2) A Diffuse-Target group, where the target sentences were diffuse while the masker was either compact or diffuse. The results indicate that the Target Timbre has a negligible effect on thresholds when the timbre of the target matches the timbre of the masker in all three groups. When there is a timbre contrast between target and masker, thresholds are significantly lower when the target is compact than when it is diffuse for all three listening groups in a Noise background. However, while this difference is maintained for the Young and Old-EFLs when the masker is Babble or Speech, speech reception thresholds in the Young-ESL group tend to be equivalent for all four combinations of target and masker timbre.

Effect of Protective Face Coverings on Sentence Recognition in Noise for Cochlear Implant Patients.

The purpose of this study was to assess the influence of talker protective face coverings on sentence recognition in noise for cochlear implant users. The AzBio sentences were recorded in three conditions: (a) without any face covering (uncovered), (b) with an N95 mask, or (c) with an N95 mask plus face shield. Target sentences were presented at 60 dB SPL, and the 10-talker masker was presented at 50 dB SPL (10 dB signal-to-noise ratio. Speech recognition for these auditory stimuli was compared across conditions for 21 adult subjects with at least 6 months of cochlear implant (CI) use. Significant deterioration in sentence recognition was observed for the N95 plus face shield (Mdn = 27% [IQR: 14%-35%]) compared with the N95 (Mdn = 72% [IQR: 55%-78%]) condition and for the N95 compared to uncovered (Mdn = 86% [IQR: 68%-91%]) condition. Talker protective face coverings have a significant influence on speech recognition in noise for CI users. More research is needed to understand the influence of visual cues with protective face coverings that include a plastic component allowing visualization of the talker's face. https://doi.org/10.23641/asha.19326395.

Remote Microphone Systems for Cochlear Implant Recipients in Small Group Settings.

Cochlear implant (CI) recipients often experience speech recognition difficulty in noise in small group settings with multiple talkers. In traditional remote microphones systems, one talker wears a remote microphone that wirelessly delivers speech to the CI processor. This system will not transmit signals from multiple talkers in a small group. However, remote microphone systems with multiple microphones allowing for adaptive beamforming may be beneficial for small group situations with multiple talkers. Specifically, a remote microphone with an adaptive multiple-microphone beamformer may be placed in the center of the small group, and the beam (i.e., polar lobe) may be automatically steered toward the direction associated with the most favorable speech-to-noise ratio. The signal from the remote microphone can then be wirelessly delivered to the CI sound processor. Alternately, each of the talkers in a small group may use a remote microphone that is part of a multi-talker network that wirelessly delivers the remote microphone signal to the CI sound processor. The purpose of this study was to compare the potential benefit of an adaptive multiple-microphone beamformer remote microphone system and a multi-talker network remote microphone system. Twenty recipients, ages 12 to 84 years, with Advanced Bionics CIs completed sentence-recognition-in-noise tasks while seated at a desk surrounded by three loudspeakers at 0, 90, and 270 degrees. These speakers randomly presented the target speech while competing noise was presented from four loudspeakers located in the corners of the room. Testing was completed in three conditions: 1) CI alone, 2) Remote microphone system with an adaptive multiple-microphone beamformer, and 3) and a multi-talker network remote microphone system each with five different signal levels (15 total conditions). Significant differences were found across all signal levels and technology conditions. Relative to the CI alone, sentence recognition improvements ranged from 14-23 percentage points with the adaptive multiple-microphone beamformer and 27-47 percentage points with the multi-talker network with superior performance for the latter remote microphone system. Both remote microphone systems significantly improved speech recognition in noise of CI recipients when listening in small group settings, but the multi-talker network provided superior performance.