Improved tactile speech perception and noise robustness using audio-to-tactile sensory substitution with amplitude envelope expansion.

Recent advances in haptic technology could allow haptic hearing aids, which convert audio to tactile stimulation, to become viable for supporting people with hearing loss. A tactile vocoder strategy for audio-to-tactile conversion, which exploits these advances, has recently shown significant promise. In this strategy, the amplitude envelope is extracted from several audio frequency bands and used to modulate the amplitude of a set of vibro-tactile tones. The vocoder strategy allows good consonant discrimination, but vowel discrimination is poor and the strategy is susceptible to background noise. In the current study, we assessed whether multi-band amplitude envelope expansion can effectively enhance critical vowel features, such as formants, and improve speech extraction from noise. In 32 participants with normal touch perception, tactile-only phoneme discrimination with and without envelope expansion was assessed both in quiet and in background noise. Envelope expansion improved performance in quiet by 10.3% for vowels and by 5.9% for consonants. In noise, envelope expansion improved overall phoneme discrimination by 9.6%, with no difference in benefit between consonants and vowels. The tactile vocoder with envelope expansion can be deployed in real-time on a compact device and could substantially improve clinical outcomes for a new generation of haptic hearing aids.

Tissue Classification After Bone-Anchored Hearing Implant Surgery: A Machine Learning Approach to Monitoring Skin Response.

HYPOTHESIS: Here, we aim to 1) expand the available evidence for the use of machine learning techniques for soft tissue classification after BCD surgery and 2) discuss the implications of such approaches toward the development of classification applications to aid in tissue monitoring. BACKGROUND: The application of machine learning techniques in the soft tissue literature has become a large field of study. One of the most commonly reported outcomes after percutaneous bone-conduction device (BCD) surgery is soft tissue health. Unfortunately, the classification of tissue around the abutment as healthy versus not healthy is a subjective process, even though such decisions can have implications for treatment (i.e., topical steroid versus surgical revision) and resources (e.g., clinician time). METHODS: We built and tested a convolutional neural network (CNN) model for the classification of tissues that were rated as "green" (i.e., healthy), "yellow" (i.e., unhealthy minor), and "red" (i.e., unhealthy severe). METHODS: Representative image samples were gathered from a regional bone-conduction amplification site (N = 398; 181 samples of green; 144 samples of yellow; 73 samples of red). The image samples were cropped, zoomed, and normalized. Feature extraction was then implemented and used as the input to train an advanced CNN model. RESULTS: Accuracy of image classification for the healthy ("green") versus not healthy ("yellow" and "red") model was approximately 87%. Accuracy of image classification for the unhealthy ("yellow") versus unhealthy ("red") model was approximately 94%. CONCLUSIONS: Monitoring tissue health is an ongoing challenge for BCD users and their clinicians not trained in soft tissue management (e.g., audiologists). If machine learning can aid in the classification of tissue health, this would have significant implications for stakeholders. Here we discuss how machine learning can be applied to tissue classification as a potential technological aid in the coming years.

The effects of extended-wear hearing aids on the localization accuracy of listeners with normal audiometric thresholds.

Extended-wear hearing aids (EWHAs) are small broadband analog amplification devices placed deeply enough in the ear canal to preserve most of the cues in the head-related transfer function. However, little is known about how EWHAs affect localization accuracy for normal hearing threshold (NHT) listeners. In this study, eight NHT participants were fitted with EWHAs and localized broadband sounds of different durations (250 ms and 4 s) and stimulus intensities (40, 50, 60, 70, and 80 dBA) in a spherical speaker array. When the EWHAs were in the active mode, localization accuracy was only slightly degraded relative to open-ear performance. However, when the EWHAs were turned off, localization performance was substantially degraded even at the highest stimulus intensities. An electro-acoustical evaluation of the EWHAs showed minimal effects of dynamic range compression on the signals and good preservation of the signal pattern for vertical polar sound localization. Between-study comparisons suggest that EWHA active mode localization accuracy is favorable compared to conventional active earplugs, and EWHA passive mode localization accuracy is comparable to conventional passive earplugs. These results suggest that the deep-insertion analog design of the EWHA is generally better at preserving localization accuracy of NHT listeners than conventional earplug devices.

[Analysis of one-year outcomes after cochlear implantation in adults with single-sided deafness].

Objectives: To investigate the outcomes of cochlear implantation in Mandarin-speaking cochlear implant (CI) users with single-sided deafness (SSD). Methods: This study was a single-center prospective cohort study. Eleven Mandarin-speaking adult SSD patients who underwent CI implantation at Capital Medical University Beijing Tongren Hospital from August 2020 to October 2021 were recruited, including 6 males and 5 females, with the age ranging from 24 to 50 years old. In a sound field with 7 loudspeakers distributed at 180°, we measured root-mean-square error(RMSE)in SSD patients at the preoperative, 1-month, 3-month, 6-month, and 12-month after switch-on to assess the improvement of sound source localization. The Mandarin Speech Perception (MSP) was used in the sound field to test the speech reception threshold (SRT) of SSD patients under different signal-to-noise locations in a steady-state noise under conditions of CI off and CI on, to reflect the head shadow effect(SSSDNNH), binaural summation effect(S0N0) and squelch effect(S0NSSD). The Tinnitus Handicap Inventory (THI) and the Visual Analogue Scale (VAS) were used to assess changes in tinnitus severity and tinnitus loudness in SSD patients at each time point. The Speech, Spatial and Qualities of Hearing Scale(SSQ) and the Nijmegen Cochlear Implantation Scale (NCIQ) were used to assess the subjective benefits of spatial speech perception and quality of life in SSD patients after cochlear implantation. SPSS 19.0 software was used for statistical analysis. Results: SSD patients showed a significant improvement in the poorer ear in hearing thresholds with CI-on compared with CI-off; The ability to localize the sound source was significantly improved, with statistically significant differences in RMSE at each follow-up time compared with the preoperative period (P<0.05). In the SSSDNNH condition, which reflects the head shadow effect, the SRT in binaural hearing was significantly improved by 6.5 dB compared with unaided condition, and the difference was statistically significant (t=6.25, P=0.001). However, there was no significant improvement in SRT between the binaural hearing condition and unaided conditions in the S0N0 and S0NSSD conditions (P>0.05). The total score of THI and three dimensions were significant decreased (P<0.05). Tinnitus VAS scores were significantly lower in binaural hearing compared to the unaided condition (P<0.001). The total score of SSQ, and the scores of speech and spatial dimensions were significant improved in binaural hearing compared to the unaided condition (P<0.001). There was no statistical difference in NCIQ questionnaire scores between preoperative and postoperative (P>0.05), and only the self-efficacy subscore showed a significant increase(Z=-2.497,P=0.013). Conclusion: CI could help Mandarin-speaking SSD patients restore binaural hearing to some extent, improve sound localization and speech recognition in noise. In addition, CI in SSD patients could suppress tinnitus, reduce the loudness of tinnitus, and improve subjective perceptions of spatial hearing and quality of life.

Otology: Hearing Loss.

Hearing loss is the cause of significant morbidity throughout the United States and the world. Because of numerous factors, such as ongoing noise exposure, poorly controlled chronic disease, and an aging population, the burden of hearing loss is expected to continue to increase. Hearing loss commonly is categorized as conductive, sensorineural, or mixed. The type of hearing loss can be determined through a combination of patient history and physical examination, and then confirmed with audiometry and tympanometry. Advanced imaging is not typically necessary, but it may be helpful in specific instances. The presentation of sudden sensorineural hearing loss should prompt urgent referral to an otolaryngologist and audiologist. Management of this condition is selective but may initially include oral corticosteroids. Management for chronic hearing loss involves the use of hearing aids, which can offer a large benefit to users but historically have been expensive and not covered by many insurance plans. Recent US legislation has made hearing aids more accessible and affordable by allowing direct-to-consumer marketing and offering over-the-counter hearing aids without a clinical evaluation.

Lexical tone recognition in multi-talker babbles and steady-state noise by Mandarin-speaking children with unilateral cochlear implants or bimodal hearing.

BACKGROUND AND OBJECTIVES: Lexical tone presents challenges to cochlear implant (CI) users especially in noise conditions. Bimodal hearing utilizes residual acoustic hearing in the contralateral side and may offer benefits for tone recognition in noise. The purpose of the present study was to evaluate tone recognition in both steady-state noise and multi-talker babbles by the prelingually-deafened, Mandarin-speaking children with unilateral CIs or bimodal hearing. METHODS: Fifty-three prelingually-deafened, Mandarin-speaking children who received CIs participated in this study. Twenty-two of them were unilateral CI users and 31 wore a hearing aid (HA) in the contralateral ear (i.e., bimodal hearing). All subjects were tested for Mandarin tone recognition in quiet and in two types of maskers: speech-spectrum-shaped noise (SSN) and two-talker babbles (TTB) at four signal-to-noise ratios (-6, 0, +6, and +12 dB). RESULTS: While no differences existed in tone recognition in quiet between the two groups, the Bimodal group outperformed the Unilateral CI group under noise conditions. The differences between the two groups were significant at SNRs of 0, +6, and +12 dB in the SSN conditions (all p < 0.05), and at SNRs of +6 and +12 dB of TTB conditions (both p < 0.01), but not significant at other conditions (p > 0.05). The TTB exerted a greater masking effect than the SSN for tone recognition in the Unilateral CI group as well as in the Bimodal group at all SNRs tested (all p < 0.05). Among demographic or audiometric variables, only age at implantation showed a weak but significant correlation with the mean tone recognition performance under the SSN conditions (r = -0.276, p = 0.045). However, when Bonferroni correction was applied to the correlation analysis results, the weak correlation became not significant. CONCLUSION: Prelingually-deafened children with CIs face challenges in tone perception in noisy environments, especially when the noise is fluctuating in amplitude such as the multi-talker babbles. Wearing a HA on the contralateral side when residual hearing permits is beneficial for tone recognition in noise.

Simulator Verification Is Potentially Beneficial for the Fitting of Softband Bone Conduction Hearing Devices in Young Children.

HYPOTHESIS: The current study employed a skull-simulator verification method to assess whether the output of softband bone conduction hearing devices (BCHDs) at the manufacturer's default settings deviated widely from the target determined by the fitting formula. BACKGROUND: Real ear analysis is utilized for the verification of the fitting of air conduction hearing devices (ACHDs) in a variety of institutions. This procedure, however, has not been used in the fitting of BCHDs, largely due to the difficulty of testing the output of these devices to temporal bones. Despite the availability of skull simulators, they have not been utilized clinically to measure BCHD output. MATERIALS AND METHODS: This prospective, single-center study enrolled 42 subjects, aged 3 months to 10 years, with microtia-atresia-associated mild-to-severe bilateral conductive hearing loss. Hearing sensitivity was evaluated behaviorally by pure tone audiometry (PTA) in 22 subjects 4 years or older (the PTA group), and by auditory brainstem response (ABR) in 20 subjects younger than 4 years (the ABR group). Following 6 months of subjects wearing the prescribed softband BCHDs, their dial level (DL) thresholds were reassessed while using their own BCHDs, configured with zero gain across all frequencies, functioning solely as a bone vibrator. These DL thresholds were inputted into the fitting formula, desired sensation level-bone conduction devices (DSL-BCD) for children, to obtain the target values of BCHD output. The simulator output of the BCHD programmed at the manufacturer's default setting was measured in response to speech presented at 55, 65, and 80 dB SPL, followed by gain adjustment based on the differences between the simulator output and the target. Aided speech intelligibility index (SII) was measured before and after the gain adjustment. RESULTS: The softband BCHDs at the manufacturer's settings generally had lower output than the prescribed target values. This difference was larger at low frequencies and low levels. Across the 12 points tested (four frequencies from 500 to 4000 Hz multiplied by three levels), 22 (52.3%) and 42 (100%) BCHDs had deviations of +7 and +5 dB, respectively, at one point or more. The gain adjustments reduced the deviation and improved the SII values at the two lower levels of speech presented. CONCLUSION: The simulator output of softband bone conduction hearing devices (BCHDs) with the manufacturer's settings may exhibit significant deviations from the formula. Objective output verification should be considered a beneficial step in BCHD fitting and is recommended when applicable.

Association between the hearing aid and mental health outcomes in people with hearing impairment: A case-control study among 28 European countries.

BACKGROUND: Hearing loss affects over 1.5 billion individuals globally, with significant implications for mental health. This study investigates the association between hearing aid use and mental health outcomes, by particularly focusing on depression and unmet mental health needs (UMHN), across a diverse international sample. METHODS: Utilizing data from the third wave of the European Health Interview Survey (EHIS), this study involved 17,660 participants with hearing impairment from 28 countries. The study examined the association between hearing aid use and mental health outcomes, including the likelihood of moderate and severe depression and UMHN due to lack of contact with general practitioners (GPs) and mental health specialists. Logistic regression models, adjusted for socio-demographic characteristics, health risk behaviours, and other relevant variables, were employed. Inverse probability weights were used to mitigate potential selection bias. RESULTS: Hearing aid usage was associated with significantly lower likelihoods of moderate depression (Odds Ratio [OR] = 0.58, 95%CI = [0.54, 0.63]) and severe depression (OR = 0.61, 95%CI = [0.55, 0.69]), compared to non-usage. Hearing aid usage was also associated with reduced UMHN due to lack of GP contact for moderate (OR = 0.82, 95%CI = [0.75, 0.89]) and severe depression (OR = 0.75, 95%CI = [0.59, 0.95]). The depression risk reductions were greater among females and higher-educated subgroups but lower in individuals aged ≥65 years. Income level and rurality also impacted UMHN due to the lack of GP contact. No associations were found between hearing aids and UMHN due to the lack of mental health specialist contact. CONCLUSIONS: Hearing aid adoption showed protective associations against mood disorders and lowered unmet primary mental healthcare needs. Tailoring intervention strategies to vulnerable sociodemographic profiles could optimize mental health benefits among those with hearing loss. Integrating hearing health services within mental healthcare delivery frameworks is vital amidst the rising global burden.

Tinnitus update: what can be done for the ringing?

Physicians will frequently encounter patients who report tinnitus. Tinnitus is a symptom whereby there is the perception of sound or sounds in the ear or head in the absence of an external source of sound. Most individuals experiencing tinnitus will have a neutral reaction to the percept, but in a small proportion of patients, tinnitus can be a debilitating symptom. When it causes burden, patients can be affected in multiple different facets of life, including impairment in sleep, hearing cognition and psychological and psychiatric well-being, often resulting in high healthcare utilisation and societal costs. Hence, chronic, disabling tinnitus is a complex condition with multifactorial causes and multiple perpetuating biopsychosocial factors. Despite efforts to increase knowledge about its pathophysiology and research into treatments, little impact on real-world clinical practice has been seen. There are no proven effective pharmacological treatments or complementary medicines specifically for chronic, disabling tinnitus. Despite this, there is a role for treating this condition through a multidisciplinary approach specifically targeting comorbid active psychiatric conditions, using hearing aids in appropriate clinical settings such as in those with a coassociated confirmed hearing loss, and specialised cognitive behavioural therapy for patients reporting bothersome tinnitus. Cognitive behavioural therapy remains the most valuable evidence-based intervention in this regard. This narrative review attempts to summarise the current understanding in terms of pathophysiology, assessment and treatment of tinnitus for the internal physician who may encounter patients with disabling, chronic tinnitus.

Effect of frequency compression on fricative perception between normal-hearing English and Mandarin listeners.

High-frequency speech information is susceptible to inaccurate perception in even mild to moderate forms of hearing loss. Some hearing aids employ frequency-lowering methods such as nonlinear frequency compression (NFC) to help hearing-impaired individuals access high-frequency speech information in more accessible lower-frequency regions. As such techniques cause significant spectral distortion, tests such as the S-Sh Confusion Test help optimize NFC settings to provide high-frequency audibility with the least distortion. Such tests have been traditionally based on speech contrasts pertinent to English. Here, the effects of NFC processing on fricative perception between English and Mandarin listeners are assessed. Small but significant differences in fricative discrimination were observed between the groups. The study demonstrates possible need for language-specific clinical fitting procedures for NFC.

Comparative Effectiveness of Personal Sound Amplification Products Versus Hearing Aids for Unilateral Hearing Loss: A Prospective Randomized Crossover Trial.

BACKGROUND: This study compared hearing outcomes with use of personal sound amplification products (PSAPs) and hearing aids (HAs) in patients with moderate to moderately severe unilateral hearing loss. METHODS: Thirty-nine participants were prospectively enrolled, and randomly assigned to use either one HA (basic or premium type) or one PSAP (basic or high-end type) for the first 8 weeks and then the other device for the following 8 weeks. Participants underwent a battery of examinations at three visits, including sound-field audiometry, word recognition score (WRS), speech perception in quiet and in noise, real-ear measurement, and self-report questionnaires. RESULTS: Functional gain was significantly higher with HAs across all frequencies (P < 0.001). While both PSAPs and HAs improved WRS from the unaided condition, HAs were superior to PSAPs. The speech recognition threshold in quiet conditions and signal-to-noise ratio in noisy conditions were significantly lower in the HA-aided condition than in the PSAP-aided condition, and in the PSAP-aided condition than in the unaided condition. Subjective satisfaction also favored HAs than PSAPs in questionnaires, Abbreviated Profile of Hearing Aid Benefit, International Outcome Inventory for Hearing Aids, and Host Institutional Questionnaire. CONCLUSION: While PSAPs provide some benefit for moderate to moderately severe unilateral hearing loss, HAs are more effective. This underscores the potential role of PSAPs as an accessible, affordable first-line intervention in hearing rehabilitation, particularly for individuals facing challenges in accessing conventional HAs.

Resonance Frequency Analysis Identifies Implant- and Host-Related Factors Associated With Bone-Anchored Hearing Implant Stability.

HYPOTHESIS: Resonance frequency analysis (RFA) is a reliable, noninvasive method to assess the stability of bone-anchored hearing implants (BAHIs), although surgical-, implant-, and host-related factors can affect its outcome. BACKGROUND: BAHI plays an important role in restoring hearing function. However, implant- and host-related factors contribute to premature implant extrusion. To mitigate this, noninvasive methods to assess implant stability, along with a better understanding of factors contributing to BAHI failure, are needed. METHODS: We evaluated the utility of RFA to quantify implant stability in sawbone (bone mimicking material), 29 human cadaveric samples, and a prospective cohort of 29 pediatric and 27 adult participants, and identified factors associated with implant stability. To validate the use of RFA in BAHI, we compared RFA-derived implant stability quotient (ISQ) estimates to peak loads obtained from mechanical push-out testing. RESULTS: ISQ and peak loads were significantly correlated (Spearman rho = 0.48, p = 0.0088), and ISQ reliably predicted peak load up to 1 kN. We then showed that in cadaveric samples, abutment length, internal table bone volume, and donor age were significantly associated with implant stability. We validated findings in our prospective patient cohort and showed that minimally invasive Ponto surgery (MIPS; versus linear incision), longer implantation durations (>16 wk), older age (>25 yr), and shorter abutment lengths (≤10 mm) were associated with better implant stability. Finally, we characterized the short-term reproducibility of ISQ measurements in sawbone and patient implants. CONCLUSIONS: Together, our findings support the use of ISQ as a measure of implant stability and emphasize important considerations that impact implant stability, including surgical method, implant duration, age, and abutment lengths.

Effect of Digital Noise Reduction in Hearing Aids on Speech Intelligibility in Both Quiet and Noisy Environments.

AIMS: Digital noise reduction (DNR) minimizes the effect of noise on speech signals by continuously monitoring frequency bands in the presence of noise. In the present study, we explored the effect of DNR technology on speech intelligibility in individuals using hearing aids (HAs) and investigated implications for daily use. METHODS AND MATERIAL: Eighteen participants with bilateral moderate sensorineural hearing loss (aged 16-45 years) were included. Bilateral receiver-in-the-ear HAs were fitted in the participants. The adaptive and nonadaptive (with a signal-to-noise ratio (SNR) of +5 and -5 dB, respectively) Turkish matrix sentence test (TURMatrix) in noise and free-field hearing assessments, including hearing thresholds with hearing aids, speech recognition thresholds (SRT), and speech discrimination scores, were conducted in two different conditions: HA in the DNR-on and DNR-off conditions. RESULTS: No significant difference was observed between free-field hearing assessments with the HA in the DNR-off and DNR-on conditions (P > 0.05). Furthermore, the adaptive and nonadaptive TURMatrix revealed significant differences between the scores under the DNR-on and DNR-off conditions (P < 0.05). Nevertheless, under the DNR-on condition, there was no correlation between free-field hearing assessments with HA and TURMatrix results (P > 0.05). However, a significant correlation was observed between SRT scores with HA and TURMatrix scores (adaptive and nonadaptive, +5 and -5 dB SNR, respectively) under the DNR-off condition (P < 0.05). CONCLUSION: Our study findings suggest that DNR can improve speech intelligibility in noisy environments. Therefore, DNR can enhance an individual's auditory comfort by improving their capacity to grasp speech in background noise.

Modeling the Intelligibility Benefit of Active Noise Cancelation in Hearing Devices That Improve Signal-to-Noise Ratio.

The extent to which active noise cancelation (ANC), when combined with hearing assistance, can improve speech intelligibility in noise is not well understood. One possible source of benefit is ANC's ability to reduce the sound level of the direct (i.e., vent-transmitted) path. This reduction lowers the "floor" imposed by the direct path, thereby allowing any increases to the signal-to-noise ratio (SNR) created in the amplified path to be "realized" at the eardrum. Here we used a modeling approach to estimate this benefit. We compared pairs of simulated hearing aids that differ only in terms of their ability to provide ANC and computed intelligibility metrics on their outputs. The difference in metric scores between simulated devices is termed the "ANC Benefit." These simulations show that ANC Benefit increases as (1) the environmental sound level increases, (2) the ability of the hearing aid to improve SNR increases, (3) the strength of the ANC increases, and (4) the hearing loss severity decreases. The predicted size of the ANC Benefit can be substantial. For a moderate hearing loss, the model predicts improvement in intelligibility metrics of >30% when environments are moderately loud (>70 dB SPL) and devices are moderately capable of increasing SNR (by >4 dB). It appears that ANC can be a critical ingredient in hearing devices that attempt to improve SNR in loud environments. ANC will become more and more important as advanced SNR-improving algorithms (e.g., artificial intelligence speech enhancement) are included in hearing devices.