Ear & Hearing

ObjectiveThis study evaluated interpeak latency (IPL) and its inter-trial variability (VIL) of the electrically evoked compound action potential (eCAP) as potential alternatives to the phase-locking value (PLV) for quantifying cochlear nerve (CN) synchrony in cochlear implant (CI) users. DesignThe IPL was assessed in postlingually deafened adults and three pediatric populations: children with auditory neuropathy spectrum disorder, cochlear nerve deficiency, and typical sensorineural hearing loss. VIL was evaluated only in adults. Their associations with temporal resolution and speech perception outcomes were evaluated. Frequency analysis was conducted to understand the impacts of eCAP recording noise on IPL, VIL, and PLV. Simulations of inter-trial jitter in the eCAP were performed to quantify how the IPL, VIL, and PLV metrics varied with increased temporal jitter. ResultseCAP traces recorded in all patient groups showed a multi-peak issue affecting the accuracy of IPL and VIL assessments. Temporal resolution and speech perception outcomes were significantly correlated with VIL but not with IPL metrics. The PLV was impacted less by recording noise than either the IPL or the VIL. Simulation results revealed that the IPL was less sensitive to the amount of inter-trial jitter in the eCAP than were the VIL and the PLV. ConclusionsThe IPL is not a reliable indicator of CN synchrony. The VIL is indicative of neural synchrony in the CN but is affected more by the eCAP recording noise than the PLV. The PLV is therefore the preferred measure for quantifying neural synchrony in the CN in CI users. Statements and DeclarationsO_ST_ABSConflict of InterestC_ST_ABSNone. IRB informationThe data reported in this study were collected for the projects that were approved by the biomedical Institutional Review Board (IRB) of The Ohio State University (IRB study #: 2017H0131, 2018H0344 and 2018N0005; PI: Shuman He), and the IRB of the University of North Carolina at Chapel Hill (IRB study #: 12-1737; PI: Shuman He). Author ContributionsSH designed this study, participated in data analysis, drafted and approved the final version of this paper. ICB participated in study design and data analysis, conducted computational modeling work, drafted and approved the final version of this paper. ZG participated in data analysis, provided critical comments, and approved the final version of this paper. RAA participated in data analysis and approved the final version of this paper. CRM participated in data collection and approved the final version of this paper. Data Availability StatementThe data that support the findings of this study are available from the authors upon reasonable request with permissions from The Ohio State University and the University of North Carolina at Chapel Hill.

Hearing loss is a highly prevalent chronic condition that degrades the quality of life. Although hearing aids provide immediate and efficient benefits to listeners with mild-to-moderate hearing loss, the prevalence of hearing aid use has been low. Consumer wireless earbuds are increasingly being equipped with the ability to amplify external sounds, which can be an affordable alternative to hearing aids. This study compared the amplification performance of non-customized Bluetooth consumer hearables to high-end hearing aids when used by people with mild-to-moderate hearing loss. We found that such a non-customized consumer device significantly enhances the speech recognition of listeners with mild-to-moderate hearing loss, although its performance did not reach the hearing aids. These results determine the extent to which inexpensive and accessible non-customized Bluetooth hearables can help people with mild-to-moderate hearing loss.

Pitch plays a fundamental role in prosody, lexical tone, and music perception, yet cochlear implant (CI) users exhibit limited temporal pitch sensitivity, particularly at higher pulse rates (e.g., 300 Hz). This study proposes a covarying pitch-encoding method, where the amplitude-modulation (AM) frequency and the pulse rate vary together in predetermined integer ratios to reinforce temporal periodicity cues. A single-channel psychophysical pitch discrimination experiment was conducted at the most apical electrode in 17 ears from 14 Cochlear CI users around reference frequencies of 50 and 300 Hz. The aims were to examine the effects of the integer ratio on pitch discrimination using the covarying method and to compare the performance of the covarying method with two conventional pitch encoding methods--pulse rate only and AM only. An additional consonant recognition task evaluated speech recognition ability. Results showed that at 50 Hz neither integer ratio nor pitch encoding method significantly affected pitch discrimination thresholds ({approx}30%). At 300 Hz, thresholds were overall higher than at 50 Hz, but the covarying method produced lower thresholds (41.8%) than the pulse rate (52.1%) and AM frequency methods (52.4%), and the covarying-pulse-rate difference was statistically significant. These results suggest that covarying stimulation can modestly enhance pitch discrimination at higher frequencies relative to conventional methods. Regression analyses revealed that temporal pitch discrimination in this psychophysical task at 50 Hz deteriorated with longer CI experience, whereas consonant recognition in a more ecologically relevant speech task improved, suggesting distinct neural adaptation mechanisms.

ObjectiveThis paper reports a noninvasive method for quantifying neural synchrony in the cochlear nerve (i.e., peripheral neural synchrony) in cochlear implant (CI) users, which allows for evaluating this physiological phenomenon in human CI users for the first time in the literature. In addition, this study assessed how peripheral neural synchrony was correlated with temporal resolution acuity and speech perception outcomes measured in quiet and in noise in post-lingually deafened adult CI users. It tested the hypothesis that peripheral neural synchrony was an important factor for temporal resolution acuity and speech perception outcomes in noise in post-lingually deafened adult CI users. DesignStudy participants included 24 post-lingually deafened adult CI users with a Cochlear Nucleus(R) device. Three study participants were implanted bilaterally, and each ear was tested separately. For each of the 27 implanted ears tested in this study, 400 sweeps of the electrically evoked compound action potential (eCAP) were measured at four electrode locations across the electrode array. Peripheral neural synchrony was quantified at each electrode location using the phase locking value (PLV), which is a measure of trial-by-trial phase coherence among eCAP sweeps/trials. Temporal resolution acuity was evaluated by measuring the within-channel gap detection threshold (GDT) using a three-alternative, forced-choice procedure in a subgroup of 20 participants (23 implanted ears). For each ear tested in these participants, GDTs were measured at two electrode locations with a large difference in PLVs. For 26 implanted ears tested in 23 participants, speech perception performance was evaluated using Consonant-Nucleus-Consonant (CNC) word lists presented in quiet and in noise at signal-to-noise ratios (SNRs) of +10 and +5 dB. Linear Mixed effect Models were used to evaluate the effect of electrode location on the PLV and the effect of the PLV on GDT after controlling for the stimulation level effects. Pearson product-moment correlation tests were used to assess the correlations between PLVs, CNC word scores measured in different conditions, and the degree of noise effect on CNC word scores. ResultsThere was a significant effect of electrode location on the PLV after controlling for the effect of stimulation level. There was a significant effect of the PLV on GDT after controlling for the effects of stimulation level, where higher PLVs (greater synchrony) led to lower GDTs (better temporal resolution acuity). PLVs were not significantly correlated with CNC word scores measured in any listening condition or the effect of competing background noise presented at a SNR of +10 dB on CNC word scores. In contrast, there was a significant negative correlation between the PLV and the degree of noise effect on CNC word scores for a competing background noise presented at a SNR of +5 dB, where higher PLVs (greater synchrony) correlated with smaller noise effects on CNC word scores. ConclusionsThis newly developed method can be used to assess peripheral neural synchrony in CI users, a physiological phenomenon that has not been systematically evaluated in electrical hearing. Poorer peripheral neural synchrony leads to lower temporal resolution acuity and is correlated with a larger detrimental effect of competing background noise presented at a SNR of 5 dB on speech perception performance in post-lingually deafened adult CI users.

ObjectivesThis preliminary study identified a missense variant in ACTG1 (NM_001614.5) in a family with autosomal dominant non-syndromic hearing loss (ADNSHL). The responsiveness of the electrically-stimulated cochlear nerve (CN) in two implanted participants with this missense change was also evaluated and reported. DesignGenetic testing was done using a custom capture panel (MiamiOtoGenes) and whole exome sequencing. The responsiveness of the electrically-stimulated CN was evaluated in two members of this family (G1 and G4) using the electrically evoked compound action potential (eCAP). eCAP results from these two participants were compared with those measured three implanted patient populations: children with cochlear nerve deficiency, children with idiopathic hearing loss and normal-sized cochlear nerves, and postligually deafened adults. ResultsSequencing of ACTG1 identified a missense c.737A>T (p. Gln246Leu) variant in ACTG1 (NM_001614.5) which is most likely the genetic cause of ADNSHL in this family. eCAP results measured in these two participants showed substantial variations. ConclusionThe missense c.737A>T (p. Gln246Leu) variant in ACTG1 (NM_001614.5) co-segregated with hearing loss in this family. The responsiveness of the electrically-stimulated CN can vary among patients with the same genetic variants, which suggests the importance of evaluating the functional status of the CN for individual CI patients.

We tested auditory spatial motion localisation in congenitally hearing impaired adult users of bilateral cochlear implants, and other hearing assistive devices. The group showed severely impaired capabilities despite extensive device use, emphasizing the role of nature in sensory development. We then investigate whether the deficit is maintained for other sensory modalities, by using an in-house sensory substitution device that provides weighted vibrotactile cues on fingertips to induce 3D spatial motion perception. The performance was significantly higher, both in the combined audio-tactile task and the tactile task itself, with accuracy comparable to typically hearing subjects. With touch, we also showed considerably fewer front-back and right-left confusions. The rapid audio-tactile binding and availability of 3D space representation through touch, point to the significant role of nurture in spatial perception development and its amodal nature. The findings show promise towards advancing multisensory solutions for spatial hearing rehabilitation. Highlights- Auditory motion localisation is severely impaired in aided congenitally hearing impaired, supporting the role of nature towards spatial development; - Binding auditory and tactile information enhances auditory spatial performance, supporting the role of nurture; - Hearing impaired individuals perform 360{degrees} motion localisation through touch with accuracy similar to typically hearing; - Surrounding spatial representation never before experienced in congenitally hearing impaired is rapidly available through an alternate modality

PurposeThe sensitivity of auditory neurons in response to electric stimulation in cochlear implant (CI) listeners may reflect neuronal health, which is a major contributor to variability in performance outcomes among CI listeners. In the current study, we explore the interplay of three outcome measures of neural sensitivity, perceptual focused thresholds, objective electrically-evoked compound action potentials (ECAP), and the Failure Index (FI). We further explore the influence of CI experience and how the measures may contribute to speech perception performance. MethodsWe examined focused perceptual threshold measures, ECAP stimulation levels and N1P2 peak response amplitudes, and ECAP input-to-output relationships in 29 adult CI recipients (14 females, 11 males, four who were bilaterally implanted). Pearson correlation analysis was performed to investigate subject specific relationships across CI electrodes, and linear mixed-effects models (LMM) were used to identify links between the outcome measures accounting for individual variation. ResultsIndividual outcomes revealed large within and across subject variability for focused thresholds, ECAP peak amplitudes, and FI. The LMMs showed, that low focused threshold measurements correspond to large ECAP peak amplitudes, while high ECAP stimulation levels reflect large ECAP peak amplitudes. Furthermore, clinical speech perception seems to be influenced by the relationship of focused thresholds and FI, with lower performance for stronger associations. ConclusionOur findings suggest that the combination of objective ECAP response measures and perceptual measures could be a robust estimate of neural health and may act as an early estimate of the speech performance abilities in CI listeners.

PurposeCurrent clinical measures used in cochlear implantation (CI) provide a broader view of speech recognition ability at word-level, often missing granular details contained at phoneme-level that may be valuable for CI mapping. This study evaluates how outcomes of Phoneme Recognition in Quiet tests (PRQ) differ from those of more commonly used word recognition tests (CVC) and outlines how these tests may be useful for different purposes in clinical adult CI care. MethodsAs part of the AuDiET (Auditory Diagnostics and Error-based Treatment) study, 23 adult postlingually deafened unilateral CI users underwent a battery of tests, including both PRQ and CVC tests. Their results were compared at the phoneme level, including an evaluation of fitness and error dispersion. ResultsPRQ had a significantly lower accuracy and fitness than CVC. The error patterns also tended to be less random and more systematic. Fitness correlated strongly and positively with accuracy, while error dispersion negatively correlated with accuracy. ConclusionThere are clear differences between PRQ and CVC outcomes in absolute accuracy and error distribution. Comparing these tests might provide clinicians with more granular insights into which areas/phonemes to target during mapping, to achieve optimal speech recognition.

A common concern in individuals with cochlear implants (CIs) is difficulty following conversations in noisy environments and social settings. The ability to accomplish these listening tasks relies on the individuals working memory abilities and draws upon limited cognitive resources to accomplish successful listening. For some individuals, allocating too much, can result deficits in speech perception and in long term detriments of quality of life. For this study, 31 CI users and NH controls completed a series of online behavioural tests and quality of life surveys, in order to investigate the relationship between visual and auditory working memory, clinical and behavioural measures of speech perception and quality of life and hearing. Results showed NH individuals were superior on auditory working memory and survey outcomes. In CI users, recall performance on the three working memory span tests declined from visual reading span to auditory listening in quiet and then listening in noise and speech perception was predictably worse when presented with noise maskers. Bilateral users performed better on each task compared to unilateral/HA and unilateral only users and reported better survey outcomes. Correlation analysis revealed that memory recall and speech perception ability were significantly correlated with sections of CIQOL and SSQ surveys along with clinical speech perception scores in CI users. These results confirm that hearing condition can predict working memory and speech perception and that working memory ability and speech perception, in turn, predict quality of life. Importantly, we demonstrate that online testing can be used as a tool to assess hearing, cognition, and quality of life in CI users.

This study investigates how well the air- and bone-conduction auditory steady-state response detects mild conductive hearing loss compared to the auditory brainstem response in young infants. Air-bone gap sizes are compared between infants with normal hearing and conductive loss using a two-group cross-sectional design. Twenty-three (500 Hz) and 22 (2000 Hz) infants (0-6 months of age) with normal hearing and 15 (500 Hz) infants with conductive loss were recruited from newborn hearing screening. Thresholds were obtained to frequency-specific air- and bone-conducted stimuli. There were no instances of conductive loss at 2000 Hz. 500 Hz mean thresholds and air-bone gap sizes were compared. Sensitivity and specificity for identifying conductive loss were measured. Overall, mean bone-conduction thresholds were similar between groups, and mean 500-Hz air conduction thresholds were higher with larger air-bone gap size for infants with conductive loss. Sensitivity and specificity for identifying conductive loss was highest for air-conduction auditory brainstem response threshold measurement compared to screening and auditory steady-state response threshold measurements. Compared to the auditory brainstem response, the variability of auditory steady-state response thresholds and air-bone gap size was too great to reliably separate normal hearing from mild conductive loss. More research is needed using infants with varying degrees of hearing loss at multiple frequencies to fully assess the appropriateness of the auditory steady-state response as a clinical diagnostic tool for an infant population.

ObjectivesThis study investigated the relationships between the cochlear nerve (CN) health and sentence-level speech perception outcomes measured in quiet and noise in postlingually deafened adult cochlear implant (CI) users. DesignStudy participants included 28 postlingually deafened adult CI users with a Cochlear(R) Nucleus device. For each participant, only one ear was tested. Neural health of the CN was assessed at three or four electrode locations across the electrode array using two parameters derived from results of the electrically evoked compound action potential (eCAP). One parameter was the phase locking value (PLV) which estimated neural synchrony in the CN. The other parameter was the sensitivity of the eCAP amplitude growth function (AGF) slope to changes in the interphase gap (IPG) of biphasic electrical pulses (i.e., the IPGEslope). Speech perception was tested using AzBio sentences in both quiet and a ten-talker babble background noise with +5 dB and +10 dB signal-to-noise ratios (SNR). IPGEslope and PLV values were averaged across electrodes for each subject, both with and without weighting by the frequency importance function (FIF) of the AzBio sentences. Pearson and Spearman correlations were used to assess the pairwise relationships between the IPGEslope, the PLV, and age. Multiple linear regression models with AzBio score as the outcome and the PLV and the IPGEslope as predictors were used to evaluate the associations between the three variables while controlling for age. ResultsThe IPGEslope and the PLV demonstrated different patterns with regards to their relationships with electrode location, age, and speech perception. The PLV, but not the IPGEslope, differed significantly across electrodes, where the apical electrodes had larger PLVs (better neural synchrony) than the basal electrodes. The IPGEslope, but not the PLV, was significantly correlated with participants age, where smaller IPGEslope values (poorer spiral ganglion neuron density) were associated with more advanced age. The PLV, but not the IPGEslope, was significantly associated with AzBio scores in the +5 dB SNR condition, where larger PLVs predicted better speech perception. Neither the PLV nor the IPGEslope was significantly associated with AzBio score in quiet or in the +10 dB SNR condition. The result patterns remained the same regardless of whether the mean values of the IPGEslope and the PLV were weighted by the AzBio FIF. The result patterns generally did not change with fitting methods or input/output scales of the AGF slopes. ConclusionsThe IPGEslope and the PLV quantify different aspects of CN health. The positive association between the PLV and AzBio scores in the +5 dB SNR condition suggests that neural synchrony is important for speech perception in adult CI users in challenging listening conditions with a relatively high noise level. The lack of association between age and the PLV indicates that reduced neural synchrony in the CN is unlikely the primary factor accounting for the greater deficits in understanding speech in noise observed in older CI users, as compared to middle-aged CI users.

Enlarged vestibular aqueduct (EVA) is a malformation associated with sensorineural hearing loss in children. Mutations in the SLC26A4 gene are also associated with EVA and may contribute to more severe hearing losses that progress, but the timescale of this progression remains unknown. Given that children undergo significant speech and language development, a better understanding of the timing and extent of hearing loss is needed for individuals who have EVA. Through a retrospective review of records in a local database, we aimed to 1) estimate the prevalence of a SLC26A4 mutation in this pediatric EVA cohort; and 2) compare hearing threshold severity and timing of progression across children who have EVA and different SLC26A4 statuses. Of 62 children with EVA, 39 had available genetic results and of these, 15 had at least one mutation of the SLC26A4 gene (38%). The children with a SLC26A4 mutation had a more severe onset of hearing loss and a more rapid progression of hearing loss over time, especially for higher frequencies, than children without a mutation in this gene. This longitudinal information may facilitate prognostic counseling to pediatric patients and better inform the audiology follow-up appointments for these families.

PurposeBest practices in audiology recommend assessing speech understanding in noisy environments, especially for those with communication difficulties. Speech-in-noise (SiN) assessments such as the QuickSIN are used for validating signal processing in hearing aids (HAs) and are linked to HA satisfaction. This project seeks to enhance QuickSIN test efficiency by applying recent advancements in automatic speech recognition (ASR) technologies. MethodTwenty-three adults with sensorineural hearing loss were fitted bilaterally with Unitron Moxi HAs and were administered the QuickSIN test in low and high reverberation environments. Testing was performed with two different HA programs: an omnidirectional program and a fixed directional microphone program. QuickSIN sentences were presented from 0{degrees} azimuth and competing babble from either 0{degrees}, laterally from 90{degrees} or 270{degrees}, or simultaneously from 90{degrees}, 180{degrees}, and 270{degrees} azimuths. Participants verbal responses to QuickSIN stimuli were scored by an audiologist and were recorded in parallel for offline transcription and scoring by ASR models from Amazon, Microsoft, NVIDIA, and Picovoice. The ASR-derived QuickSIN scores were compared to the corresponding audiologist-derived scores. ResultsRepeated Measures ANOVA results revealed that all ASR models overestimated the QuickSIN scores across most test conditions. Bland-Altman analyses showed that the Amazon ASR model had the least bias and the narrowest range for the limits of agreement, in comparison to the manual scoring by an experienced audiologist. ConclusionsSome ASR models, such as Amazon, demonstrated performance comparable to that of an audiologist in automatically scoring QuickSIN tests. However, further refinements are necessary to increase the robustness of the ASR models in scoring low SNR loss test conditions.

The human auditory system decomposes complex sounds into distinct components via a collection of processing steps. Knowing whether Spiral Ganglion Cells (SGCs) play an active role in the decoding of complex sounds can facilitate the development of Cochlear Implant (Cl) coding strategies and clinical assessment tools. Early animal studies reported SGCs being similar across different characteristic frequencies (CFs). In this study, human electrically evoked compound action potentials (eCAPs) were analysed to probe the relationship between the reciprocal of CF and the duration of the eCAP. A significant relationship could indicate that SGCs may not simply be passive cables. eCAP datasets from 6 published studies (175 Cl users, 1243 recordings) were analysed and their peaks were automatically labelled. The nlp2 latency was derived for each recording as a proxy of the action potential duration. The CF of each recording was estimated by mapping the average insertion angle of the electrode to the human SGC map. A weak but statistically significant relationship was observed between the n1p2 latency and the reciprocal of CF (random-effects model with random intercepts for subject, r = 0.09, p = 0.024, n= 450) supporting the hypothesis that lower CF is associated with slower repolarisation (longer n1p2 latency) in human spiral ganglion cells.

IntroductionClinically, the audiogram is the most commonly used measure when evaluating hearing loss and fitting hearing aids. As an extension, we present the loudness audiogram, which does not only show auditory thresholds but also visualises the full course of loudness perception. MethodsIn a group of 15 bimodal users, loudness growth was measured with the cochlear implant and hearing aid separately using a loudness scaling procedure. Loudness growth curves were constructed, using a novel loudness function, for each modality and then integrated in a graph plotting frequency, stimulus intensity level, and loudness perception. Bimodal benefit, defined as the difference between wearing a cochlear implant and hearing aid together versus wearing only a cochlear implant, was assessed for multiple speech outcomes. ResultsLoudness growth was related to bimodal benefit for speech understanding in noise and to some aspects of speech quality. No correlations between loudness and speech in quiet were found. Patients who had predominantly unequal loudness input from the hearing aid, gained more bimodal benefit for speech understanding in noise compared to those patients whose hearing aid provided mainly equivalent input. DiscussionFitting the cochlear implant and a contralateral hearing aid to create equal loudness at all frequencies may not always be beneficial for speech understanding.

In conventional hearing-aid personalisation, clinicians cannot hear what their patients hear, and patients cannot often reliably detect or describe what they hear. Self-adjustment avoids this issue but requires user controls that adjust hearing-aid signal processing parameters to be effective, efficient and easy. In this study, we explored (a) the roles of interface complexity and stimulus type in the self-adjustment of hearing-aid gain, and (b) how well individuals can adjust one sound to match another to assess the same interfaces and stimuli. Adult hearing-aid users with mild to moderate symmetrical sensorineural hearing loss repeatedly adjusted the gain (a) to their preference from individual prescription (n = 41) and (b) to match their previous preferences from a random starting point (n = 32) using three interfaces representing different bass/mid/treble configurations and three stimuli (music, speech and speech-in-noise). The large interindividual variability in self-adjusted gains clustered into three patterns of deviation from initial prescription: increased relative bass, overall gain reduction, and close to initial prescription. There were no substantial effects of interface nor stimulus on self-adjustment reliability (median {sigma} = 2.8 dB), whereas absolute sound-matching error increased with increasing interface complexity and centre frequency. Neither individual matching accuracy nor questionnaire responses predicted either self-adjusted gains or reliability. Overall, these results show that many - but not all - hearing-aid users can adjust gains with reasonable reliability, and while it can be difficult to predict the behaviour from the individual, the individual applies a similar self-adjustment behaviour across different interfaces and stimuli.

ObjectivePersons with hearing aids or cochlear implants often have difficulty understanding speech well despite amplification, especially in noisy environments. Auditory training can help their brain refine their listening skills. The current study aimed to determine the efficacy of the ALICE program, a self-guided home-based health care program including monitoring, training and counselling. MethodA multicentric study was carried out, including hearing aid centers and a cochlear implant center in Flanders (Belgium). Participants were assigned randomly to an intervention or control group. Participants in the intervention group received a tailored flow of exercises that could be streamed to the device or presented in sound field. All participants were tested before and after 8 weeks using sentences in noise and different self-reports. ResultsParticipants in the intervention group were compliant during the 8-week training period. Significant on-task improvements were observed, as well as improved speech in noise understanding for the intervention group only. The self-report data did not reveal changes following the intervention. ConclusionsOur clinical trial shows that the self-guided ALICE training program is effective at improving the auditory systems ability to parse untrained speech in noise. This enhancement in speech in noise performance is specific to the training group, as the control group did not improve. The results of the clinical trials imply that ALICE can be used as a scalable, accessible, and safe hearing care intervention.

ObjectivesThe auditory brainstem response (ABR) is an essential tool in screening for and diagnosing infant hearing loss, and its results drive decisions regarding interventions and hearing habilitation with impacts extending far into a childs future. Despite the traditional ABR exams usefulness, there is an identified need to develop faster, more informative exams. The parallel ABR (pABR) measures responses to all frequencies of interest in both ears all at once, rather than the traditional series of single-frequency measurements in one ear at a time, greatly speeding the diagnostic exam. The pABR has been shown to be effective at quickly measuring frequency-specific responses in adults with normal hearing, but it has not yet been tested in people with hearing loss. The goal of this study was to determine the accuracy and speed of the pABR for estimating hearing thresholds in a clinic-like setting. DesignSeventy adults with widely varying sensorineural hearing loss configurations were recruited to participate in this study. We measured thresholds at octave frequencies in two ways: the behavioral audiogram, serving as the ground truth, and using the pABR with a custom-designed interactive user interface. Accuracy was determined through threshold correlation coefficients as well as absolute error in decibels. Acquisition time was assessed as the time from measurement start to determination of the final threshold. To determine the pABRs speed advantages, a subset of participants was invited back and their thresholds estimated a third time, using a commercially available clinical system to serially measure ABR waveforms. Speedup was assessed in terms of the raw difference in acquisition time in minutes and as the ratio between measurement times made with the two ABR paradigms. ResultsThresholds estimated with pABR highly correlated with the behavioral audiogram ground truth. The correlation was 0.90 (0.88-0.92, 95% confidence interval) across all ears and frequencies. 79% of pABR thresholds were within one 10-dB step-size of the behavioral threshold. The pABR was faster in all ten participants where traditional serial ABR was also recorded, with a mean recording time of 28 minutes to estimate ten pABR thresholds (500-8000 Hz in each ear) versus 70 minutes to estimate eight serial thresholds (500-4000 Hz in each ear), or a mean reduction of 42 minutes. The median speedup ratio was 2.5x. ConclusionsThe pABR provides accurate threshold estimates with greatly reduced measurement time compared to traditional methods. Given these results and other advantages related to its design, the pABR holds promise as a clinical tool that can be deployed to commercial systems in the near future.

80% of primary school children suffer from glue ear which may impair hearing at a critical time for speech acquisition and social development. An online application, DigiBel, has been developed primarily to identify individuals with conductive hearing impairment who may benefit from temporary use of bone-conduction (BC) assistive technology in the community. This preliminary study aims to determine the screening accuracy and usability of DigiBel self-assessed air-conduction (AC) pure tone audiometry (PTA) in adult volunteers with simulated hearing impairment prior to formal clinical validation. Healthy adults, each with one ear plugged, underwent standard automated AC PTA (reference test) and DigiBel audiometry in quiet community settings. Threshold measurements were compared across six tone frequencies and DigiBel test-retest reliability was calculated. The accuracy of DigiBel for detecting more than 20 decibels of hearing impairment was assessed. 30 adults (30 unplugged ears and 30 plugged ears) completed both audiometry tests. DigiBel had 100% sensitivity (95%CI 87.23-100) and 72.73% (95%CI 54.48-86.70) specificity in detecting hearing impairment. Threshold mean bias was insignificant except at 4000 and 8000Hz where a small but significant over-estimation of threshold measurement was identified. All 24 subjects completing feedback rated the DigiBel test good or excellent and 21(87.5%) agreed or strongly agreed that they would be able to do the test at home without help. This study supports the potential use of DigiBel as a screening tool for hearing impairment. The findings will be used to improve the software further and undertake a formal clinical trial of AC and BC audiometry in individuals with suspected conductive hearing impairment. Author SummaryHearing loss is a major global health issue. It can affect many aspects of life such as education, employment, communication, and result in social isolation. Two thirds of people with severe hearing loss live in low and middle countries with poor access both to hearing testing (audiometry) or conventional hearing aids. Several software applications (apps) like DigiBel, studied here, have been developed to enable individuals to test their own hearing in the community. Uniquely, DigiBel has the additional potential to identify individuals with hearing loss who could derive immediate hearing support from an affordable and rechargeable bone-conduction headphone / microphone kit while waiting specialist care. This initial study of DigiBel provides confirmation that the app is easy to use and accurate at detecting simulated hearing impairment. It lays the groundwork for future clinical studies to assess DigiBels performance in children and adults with hearing impairment.

Electric stimulation via a Cochlear Implant (CI) enables people with severe to profound sensorineural hearing loss to regain speech understanding and music appreciation and thus allowing them to actively engage in social life. Three main manufacturers (Cochlear, MED-EL and Advanced Bionics "AB") have been offering CI systems, thus challenging CI recipients and Otolaryngologists with a difficult decision, as currently no comprehensive overview or meta-analyses on performance outcome following CI implantation is available. The main goal of this scoping review is to provide evidence that data and standardized speech and music performance tests are available for performing such comparisons. To this end, a literature search was conducted to find studies that address speech and music outcomes in CI recipients. From a total of 1592 papers, 188 paper abstracts were analyzed and 147 articles were found suitable for examination of full text. From which, 42 studies were included for synthesis. A total of 16 studies used the consonant-nucleus-consonant (CNC) word recognition test in quiet at 60db SPL. We found that aside from technical comparisons, only very few publications compare speech outcomes across manufacturers of CI systems. Evidence suggests though, that these data are available in large CI centers in Germany and US. Future studies should therefore leverage large data cohorts to perform such comparisons that could provide critical evaluation criteria and assist both CI recipients and Otolaryngologists to make informed performance-based decisions.