A single dose of AC102 restores hearing in a guinea pig model of noise-induced hearing loss to almost prenoise levels.

Although sudden sensorineural hearing loss (SSNHL) is a serious condition, there are currently no approved drugs for its treatment. Nevertheless, there is a growing understanding that the cochlear pathologies that underlie SSNHL include apoptotic death of sensory outer hair cells (OHCs) as well as loss of ribbon synapses connecting sensory inner hair cells (IHCs) and neurites of the auditory nerve, designated synaptopathy. Noise-induced hearing loss (NIHL) is a common subtype of SSNHL and is widely used to model hearing loss preclinically. Here, we demonstrate that a single interventive application of a small pyridoindole molecule (AC102) into the middle ear restored auditory function almost to prenoise levels in a guinea pig model of NIHL. AC102 prevented noise-triggered loss of OHCs and reduced IHC synaptopathy suggesting a role of AC102 in reconnecting auditory neurons to their sensory target cells. Notably, AC102 exerted its therapeutic properties over a wide frequency range. Such strong improvements in hearing have not previously been demonstrated for other therapeutic agents. In vitro experiments of a neuronal damage model revealed that AC102 protected cells from apoptosis and promoted neurite growth. These effects may be explained by increased production of adenosine triphosphate, indicating improved mitochondrial function, and reduced levels of reactive-oxygen species which prevents the apoptotic processes responsible for OHC death. This action profile of AC102 might be causal for the observed hearing recovery in in vivo models.

Application of Noise Reduction Earplugs in Patients undergoing Total Knee Arthroplasty: A Retrospective Study.

BACKGROUND: Patients undergoing total knee arthroplasty (TKA) need to tolerate the effects of noise. MATERIALS AND METHODS: This study retrospectively analyzed the clinical data of 167 TKA patients at The Affiliated Hospital of Southwest Medical University from April 2019 to April 2021. A total of 154 patients who met inclusion criteria were divided into the conventional noise reduction management group (CMG) and the noise reduction earplug group (EPG), following different management schemes. The CMG received routine noise reduction management after surgery, while the EPG used noise reduction earplugs based on the CMG. The clinical indexes of the two groups were compared. RESULTS: In this study, 79 patients were included in the CMG, and 75 patients were included in the EPG. The results showed that the Pittsburgh Sleep Quality Index (PSQI) scores of both groups 2 weeks after surgery were significantly lower than those before management (ZEPG = 5.995, ZCMG = 4.109, all P < 0.001), and the EPG exhibited a significantly lower PSQI score than the CMG (Z = -2.442, P < 0.05). Two weeks after surgery, the EPG had significantly lower levels of systolic blood pressure (ZSBP = -4.303) and diastolic blood pressure (ZDBP = -3.115), as well as lower scores on the Hospital Anxiety and Depression Scale-Anxiety (HADS-A; ZHADS-A = -7.140) and Hospital Anxiety and Depression Scale-Depression (HADS-D; ZHADS-D = -4.545) compared to the CMG (all P < 0.05). In addition, no significant correlation existed between the duration of wearing earplugs and the HADS-A and HADS-D scores (r = -0.201, r = -0.002, P > 0.05). CONCLUSION: Noise reduction earplugs can improve sleep quality and regulate negative emotions of patients undergoing TKA treatment through a complex mechanism involving noise, which is beneficial to the prognosis of the disease.

Research on the characteristics of EV interior sound quality and its dynamic active control system design and development un-der accelerated driving conditions.

In order to improve the interior sound quality of Electric Vehicles (EV), solve the problem of low sense of power and comfort of the interior sound as well as the large electromagnetic excitation order noise of motor and the sharp interior sound, this article designs a dynamic active sound control system for EV under accelerated driving conditions. Firstly, by comparing and analyzing the sound spectrum characteristics of fuel vehicle (FV) and EV during acceleration, a short-time Fourier transform (STFT) is adopted to extract and synthesize the engine sound. Secondly, the influence of the engine order composition and the energy distribution in the frequency domain on the sound quality of the vehicle is analyzed, and an active control system for sound quality is proposed. And the software and hardware development of the active control sound system is completed. Finally, through real-vehicle testing and verification, the sense of comfort and power of the EV interior sound has been greatly improved during acceleration, and the total value of interior sound can meet the requirement. The sound pressure level and loudness of interior sound have been increased, and the sharpness of the sound inside the vehicle has been improved, with a maximum reduction of 1.0acum.

[Horizontal sound localization in presence of noise in normal-hearing young adults].

Objective: This study investigates the effect of signal-to-noise ratio (SNR), frequency, and bandwidth on horizontal sound localization accuracy in normal-hearing young adults. Methods: From August 2022 to December 2022, a total of 20 normal-hearing young adults, including 7 males and 13 females, with an age range of 20 to 35 years and a mean age of 25.4 years, were selected to participate in horizontal azimuth recognition tests under both quiet and noisy conditions. Six narrowband filtered noise stimuli were used with central frequencies (CF) of 250, 2 000, and 4 000 Hz and bandwidths of 1/6 and 1 octave. Continuous broadband white noise was used as the background masker, and the signal-to-noise ratio (SNR) was 0, -3, and -12 dB. The root-mean-square error (RMS error) was used to measure sound localization accuracy, with smaller values indicating higher accuracy. Friedman test was used to compare the effects of SNR and CF on sound localization accuracy, and Wilcoxon signed-rank test was used to compare the impact of the two bandwidths on sound localization accuracy in noise. Results: In a quiet environment, the RMS error in horizontal azimuth in normal-hearing young adults ranged from 4.3 to 8.1 degrees. Sound localization accuracy decreased with decreasing SNR: at 0 dB SNR (range: 5.3-12.9 degrees), the difference from the quiet condition was not significant (P>0.05); however, at -3 dB (range: 7.3-16.8 degrees) and -12 dB SNR (range: 9.4-41.2 degrees), sound localization accuracy significantly decreased compared to the quiet condition (all P<0.01). Under noisy conditions, there were differences in sound localization accuracy among stimuli with different frequencies and bandwidths, with higher frequencies performing the worst, followed by middle frequencies, and lower frequencies performing the best, with significant differences (all P<0.01). Sound localization accuracy for 1/6 octave stimuli was more susceptible to noise interference than 1 octave stimuli (all P<0.01). Conclusions: The ability of normal-hearing young adults to localize sound in the horizontal plane in the presence of noise is influenced by SNR, CF, and bandwidth. Noise with SNRs of ≥-3 dB can lead to decreased accuracy in narrowband sound localization. Higher CF signals and narrower bandwidths are more susceptible to noise interference.

The word-with-noise test: test-retest reliability in normal-hearing adults. / Teste de palavras no ruído: confiabilidade no teste-reteste em adultos normo-ouvintes.

PURPOSE: To investigate the reliability of the Word-with-Noise Test in a group of normal-hearing adults. METHODS: Forty-five normal-hearing adult subjects participated in the research. The interval between the first and second assessment was 14 to 28 days, performed during the same time of the day and by the same evaluator. The comparison analysis between the test and the retest was performed considering the general result of the ears, totaling 90 ears evaluated. The inferential analysis included the comparison of the situations in the first and second assessment using the Wilcoxon Test, calculation, and interpretation of the Intraclass Correlation Index. RESULTS: There was a statistically significant difference between the test and retest performances. The intraclass correlation coefficients obtained were indicative of good reliability (r=0.759; p<0.001) for the monosyllabic stimulus and moderate reliability (r=0.631; p<0.001) for the disyllabic stimulus. CONCLUSION: The Word-with-Noise Test demonstrated satisfactory reliability for both the monosyllabic and disyllabic stimuli.

OBJETIVO: Investigar a confiabilidade do Teste de Palavras no Ruído em um grupo de adultos normo-ouvintes. MÉTODO: Participaram da pesquisa 45 sujeitos adultos normo-ouvintes. O intervalo entre a primeira e a segunda avaliação foi de 14 a 28 dias, realizadas no mesmo turno do dia e pelo mesmo avaliador. A análise de comparação entre teste e reteste foi realizada considerando o resultado geral das orelhas, totalizando 90 orelhas avaliadas. A análise inferencial incluiu a comparação das situações na primeira e segunda avaliação por meio do Teste de Wilcoxon, cálculo e interpretação do Índice de Correlação Intraclasse. RESULTADOS: Houve diferença estatisticamente significante entre os desempenhos no teste e reteste. Os coeficientes de correlação intraclasse obtidos foram indicativos de boa confiabilidade (r=0,759; p<0,001) para o estímulo monossilábico e de moderada confiabilidade (r=0,631; p<0,001) para o dissilábico. CONCLUSÃO: O Teste de Palavras no Ruído demonstrou satisfatória confiabilidade tanto para o estímulo monossilábico, quanto para o dissilábico.

Used to Be a Dime, Now It's a Dollar: Revised Speech Perception in Noise Key Word Predictability Revisited 40 Years On.

PURPOSE: Almost 40 years after its development, in this article, we reexamine the relevance and validity of the ubiquitously used Revised Speech Perception in Noise (R-SPiN) sentence corpus. The R-SPiN corpus includes "high-context" and "low-context" sentences and has been widely used in the field of hearing research to examine the benefit derived from semantic context across English-speaking listeners, but research investigating age differences has yielded somewhat inconsistent findings. We assess the appropriateness of the corpus for use today in different English-language cultures (i.e., British and American) as well as for older and younger adults. METHOD: Two hundred forty participants, including older (60-80 years) and younger (19-31 years) adult groups in the the United Kingdom and United States, completed a cloze task consisting of R-SPiN sentences with the final word removed. Cloze, as a measure of predictability, and entropy, as a measure of response uncertainty, were compared between culture and age groups. RESULTS: Most critically, of the 200 "high-context" stimuli, only around half were assessed as highly predictable for older adults (United Kingdom: 109; United States: 107); and fewer still, for younger adults (United Kingdom: 75; United States: 81). We also found dominant responses to these "high-context" stimuli varied between cultures, with U.S. responses being more likely to match the original R-SPiN target. CONCLUSIONS: Our findings highlight the issue of incomplete transferability of corpus items across English-language cultures as well as diminished equivalency for older and younger adults. By identifying relevant items for each population, this work could facilitate the interpretation of inconsistent findings in the literature, particularly relating to age effects.

(Why) Do Transparent Hearing Devices Impair Speech Perception in Collocated Noise?

Hearing aids and other hearing devices should provide the user with a benefit, for example, compensate for effects of a hearing loss or cancel undesired sounds. However, wearing hearing devices can also have negative effects on perception, previously demonstrated mostly for spatial hearing, sound quality and the perception of the own voice. When hearing devices are set to transparency, that is, provide no gain and resemble open-ear listening as well as possible, these side effects can be studied in isolation. In the present work, we conducted a series of experiments that are concerned with the effect of transparent hearing devices on speech perception in a collocated speech-in-noise task. In such a situation, listening through a hearing device is not expected to have any negative effect, since both speech and noise undergo identical processing, such that the signal-to-noise ratio at ear is not altered and spatial effects are irrelevant. However, we found a consistent hearing device disadvantage for speech intelligibility and similar trends for rated listening effort. Several hypotheses for the possible origin for this disadvantage were tested by including several different devices, gain settings and stimulus levels. While effects of self-noise and nonlinear distortions were ruled out, the exact reason for a hearing device disadvantage on speech perception is still unclear. However, a significant relation to auditory model predictions demonstrate that the speech intelligibility disadvantage is related to sound quality, and is most probably caused by insufficient equalization, artifacts of frequency-dependent signal processing and processing delays.

The impact of co-exposure to air and noise pollution on the incidence of metabolic syndrome from a health checkup cohort.

Previous studies have found associations between the incidence of metabolic syndrome (MetS) and exposure to air pollution or road traffic noise. However, investigations on environmental co-exposures are limited. This study aimed to investigate the association between co-exposure to air pollution and road traffic noise and MetS and its subcomponents. Participants living in Taipei City who underwent at least two health checkups between 2010 and 2016 were included in the study. Data were sourced from the MJ Health database, a longitudinal, large-scale cohort in Taiwan. The monthly traffic noise exposure (Lden and Lnight) was computed using a dynamic noise map. Monthly fine particulate data at one kilometer resolution were computed from satellite imagery data. Cox proportional hazards regression models with month as the underlying time scale were used to estimate hazard ratios (HRs) for the impact of PM2.5 and road traffic noise exposure on the risk of developing MetS or its subcomponents. Data from 10,773 participants were included. We found significant positive associations between incident MetS and PM2.5 (HR: 1.88; 95% CI 1.67, 2.12), Lden (HR: 1.10; 95% CI 1.06, 1.15), and Lnight (HR: 1.07; 95% CI 1.02, 1.13) in single exposure models. Results further showed significant associations with an elevated risk of incident MetS in co-exposure models, with HRs of 1.91 (95% CI 1.69, 2.16) and 1.11 (95% CI 1.06, 1.16) for co-exposure to PM2.5 and Lden, and 1.90 (95% CI 1.68, 2.14) and 1.08 (95% CI 1.02, 1.13) for co-exposure to PM2.5 and Lnight. The HRs for the co-exposure models were higher than those for models with only a single exposure. This study provides evidence that PM2.5 and noise exposure may elevate the risk of incident MetS and its components in both single and co-exposure models. Therefore, preventive approaches to mitigate the risk of MetS and its subcomponents should consider reducing exposure to PM2.5 and noise pollution.

Association of early-life exposure to air and noise pollution with youth mental health: findings from the ALSPAC cohort.

BACKGROUND: Increasing evidence suggests that air pollution exposure contributes to the development of mental health problems, including psychosis and depression. However, little is known about the importance of early-life exposure, nor the potential role of noise pollution, a correlate of air pollution. We examined the association of exposure to air and noise pollution from pregnancy to age 12 years with three mental health problems assessed at ages 12, 18, and 24 years. METHODS: Data were from the Avon Longitudinal Study of Parents and Children (ALSPAC), which tracks the development of about 14 000 babies who had expected delivery dates between April 1, 1991, and Dec 31, 1992, in Avon, UK. This was linked with novel data on nitrogen dioxide, PM2·5, and noise pollution in pregnancy, childhood (ages 1-9 years), and adolescence (ages 10-12 years). Psychotic experiences, depression, and anxiety were measured at ages 12, 18, and 24 years. Logistic regression models were controlled for individual-level, family-level, and area-level confounders, and e-values were calculated to estimate residual confounding. FINDINGS: Participants exposed to higher PM2.5, particularly during pregnancy, had greater odds for psychotic experiences (adjusted odds ratio 1·17 [95% CI 1·05-1·30]) and depression (1·11 [1·01-1·22]). There was little evidence associating nitrogen dioxide or noise pollution with psychotic experiences or depression. Conversely, higher nitrogen dioxide (but not PM2·5) exposure in pregnancy (1·16 [1·01-1·33]), and higher noise pollution in childhood (1·20 [1·06-1·37]) and adolescence (1·17 [1·02-1·35]), were associated with greater odds for anxiety. INTERPRETATION: Our study builds on evidence linking air pollution to psychosis and depression and provides rare longitudinal evidence linking noise pollution to anxiety. Our findings indicate that air pollution exposure earlier in development (eg, during pregnancy) might be particularly important, and suggest a degree of specificity in terms of pollutant-outcome associations. If causal, our findings suggest that interventions to reduce air pollution would improve global mental health. FUNDING: Wellcome Trust, UK Medical Research Council-Wellcome, and University of Bristol.

Transcriptional-profile changes in the medial geniculate body after noise-induced tinnitus.

Tinnitus is a disturbing condition defined as the occurrence of acoustic hallucinations with no actual sound. Although the mechanisms underlying tinnitus have been explored extensively, the pathophysiology of the disease is not completely understood. Moreover, genes and potential treatment targets related to auditory hallucinations remain unknown. In this study, we examined transcriptional-profile changes in the medial geniculate body after noise-induced tinnitus in rats by performing RNA sequencing and validated differentially expressed genes via quantitative polymerase chain reaction analysis. The rat model of tinnitus was established by analyzing startle behavior based on gap-pre-pulse inhibition of acoustic startles. We identified 87 differently expressed genes, of which 40 were upregulated and 47 were downregulated. Pathway-enrichment analysis revealed that the differentially enriched genes in the tinnitus group were associated with pathway terms, such as coronavirus disease COVID-19, neuroactive ligand-receptor interaction. Protein-protein-interaction networks were established, and two hub genes (Rpl7a and AC136661.1) were identified among the selected genes. Further studies focusing on targeting and modulating these genes are required for developing potential treatments for noise-induced tinnitus in patients.

Synaptic ribbon dynamics after noise exposure in the hearing cochlea.

Moderate noise exposure induces cochlear synaptopathy, the loss of afferent ribbon synapses between cochlear hair cells and spiral ganglion neurons, which is associated with functional hearing decline. Prior studies have demonstrated noise-induced changes in the distribution and number of synaptic components, but the dynamic changes that occur after noise exposure have not been directly visualized. Here, we describe a live imaging model using RIBEYE-tagRFP to enable direct observation of pre-synaptic ribbons in mature hearing mouse cochleae after synaptopathic noise exposure. Ribbon number does not change, but noise induces an increase in ribbon volume as well as movement suggesting unanchoring from synaptic tethers. A subgroup of basal ribbons displays concerted motion towards the cochlear nucleus with subsequent migration back to the cell membrane after noise cessation. Understanding the immediate dynamics of synaptic damage after noise exposure may facilitate identification of specific target pathways to treat cochlear synaptopathy.

Interaction of barn owl leading edge serrations with freestream turbulence.

The silent flight of barn owls is associated with wing and feather specialisations. Three special features are known: a serrated leading edge that is formed by free-standing barb tips which appears as a comb-like structure, a soft dorsal surface, and a fringed trailing edge. We used a model of the leading edge comb with 3D-curved serrations that was designed based on 3D micro-scans of rows of barbs from selected barn-owl feathers. The interaction of the flow with the serrations was measured with Particle-Image-Velocimetry in a flow channel at uniform steady inflow and was compared to the situation of inflow with freestream turbulence, generated from the turbulent wake of a cylinder placed upstream. In steady uniform flow, the serrations caused regular velocity streaks and a flow turning effect. When vortices of different size impacted the serrations, the serrations reduced the flow fluctuations downstream in each case, exemplified by a decreased root-mean-square value of the fluctuations in the wake of the serrations. This attenuation effect was stronger for the spanwise velocity component, leading to an overall flow homogenization. Our findings suggest that the serrations of the barn owl provide a passive flow control leading to reduced leading-edge noise when flying in turbulent environments.

Linear and nonlinear integrate-and-fire neurons driven by synaptic shot noise with reversal potentials.

The steady-state firing rate and firing-rate response of the leaky and exponential integrate-and-fire models receiving synaptic shot noise with excitatory and inhibitory reversal potentials is examined. For the particular case where the underlying synaptic conductances are exponentially distributed, it is shown that the master equation for a population of such model neurons can be reduced from an integrodifferential form to a more tractable set of three differential equations. The system is nevertheless more challenging analytically than for current-based synapses: where possible, analytical results are provided with an efficient numerical scheme and code provided for other quantities. The increased tractability of the framework developed supports an ongoing critical comparison between models in which synapses are treated with and without reversal potentials, such as recently in the context of networks with balanced excitatory and inhibitory conductances.

Aberrant thalamocortical connectivity and shifts between the resting state and task state in patients with schizophrenia.

Prominent pathological hypotheses for schizophrenia include auditory processing deficits and dysconnectivity within cerebral networks. However, most neuroimaging studies have focused on impairments in either resting-state or task-related functional connectivity in patients with schizophrenia. The aims of our study were to examine (1) blood oxygen level-dependent (BOLD) signals during auditory steady-state response (ASSR) tasks, (2) functional connectivity during the resting-state and ASSR tasks and (3) state shifts between the resting-state and ASSR tasks in patients with schizophrenia. To reduce the functional consequences of scanner noise, we employed resting-state and sparse sampling auditory fMRI paradigms in 25 schizophrenia patients and 25 healthy controls. Auditory stimuli were binaural click trains at frequencies of 20, 30, 40 and 80 Hz. Based on the detected ASSR-evoked BOLD signals, we examined the functional connectivity between the thalamus and bilateral auditory cortex during both the resting state and ASSR task state, as well as their alterations. The schizophrenia group exhibited significantly diminished BOLD signals in the bilateral auditory cortex and thalamus during the 80 Hz ASSR task (corrected p < 0.05). We observed a significant inverse relationship between the resting state and ASSR task state in altered functional connectivity within the thalamo-auditory network in schizophrenia patients. Specifically, our findings demonstrated stronger functional connectivity in the resting state (p < 0.004) and reduced functional connectivity during the ASSR task (p = 0.048), which was mediated by abnormal state shifts, within the schizophrenia group. These results highlight the presence of abnormal thalamocortical connectivity associated with deficits in the shift between resting and task states in patients with schizophrenia.

Alpha-Band Dynamics of Hearing Aid Wearers Performing the Repeat-Recall Test (RRT).

This study measured electroencephalographic activity in the alpha band, often associated with task difficulty, to physiologically validate self-reported effort ratings from older hearing-impaired listeners performing the Repeat-Recall Test (RRT)-an integrative multipart assessment of speech-in-noise performance, context use, and auditory working memory. Following a single-blind within-subjects design, 16 older listeners (mean age = 71 years, SD = 13, 9 female) with a moderate-to-severe degree of bilateral sensorineural hearing loss performed the RRT while wearing hearing aids at four fixed signal-to-noise ratios (SNRs) of -5, 0, 5, and 10 dB. Performance and subjective ratings of listening effort were assessed for complementary versions of the RRT materials with high/low availability of semantic context. Listeners were also tested with a version of the RRT that omitted the memory (i.e., recall) component. As expected, results showed alpha power to decrease significantly with increasing SNR from 0 through 10 dB. When tested with high context sentences, alpha was significantly higher in conditions where listeners had to recall the sentence materials compared to conditions where the recall requirement was omitted. When tested with low context sentences, alpha power was relatively high irrespective of the memory component. Within-subjects, alpha power was related to listening effort ratings collected across the different RRT conditions. Overall, these results suggest that the multipart demands of the RRT modulate both neural and behavioral measures of listening effort in directions consistent with the expected/designed difficulty of the RRT conditions.

Adaptive selection of local and non-local attention mechanisms for speech enhancement.

In speech enhancement tasks, local and non-local attention mechanisms have been significantly improved and well studied. However, a natural speech signal contains many dynamic and fast-changing acoustic features, and focusing on one type of attention mechanism (local or non-local) cannot precisely capture the most discriminative information for estimating target speech from background interference. To address this issue, we introduce an adaptive selection network to dynamically select an appropriate route that determines whether to use the attention mechanisms and which to use for the task. We train the adaptive selection network using reinforcement learning with a developed difficulty-adjusted reward that is related to the performance, complexity, and difficulty of target speech estimation from the noisy mixtures. Consequently, we propose an Attention Selection Speech Enhancement Network (ASSENet) with the innovative dynamic block that consists of an adaptive selection network and a local and non-local attention based speech enhancement network. In particular, the ASSENet incorporates both local and non-local attention and develops the attention mechanism selection technique to explore the appropriate route of local and non-local attention mechanisms for speech enhancement tasks. The results show that our method achieves comparable and superior performance to existing approaches with attractive computational costs.

Female frogs communicate with males through blinking.

Blinking is a behavior unique to animal taxa with motile eyelids, such as most amphibians and reptiles as well as all birds and mammals1. Eyelid movement has physiological functions, such as lubricating the cornea and washing away dust, but its potential signaling functions are not well understood1,2. The use of eyeblinks as a social signal is currently thought to be restricted to some primates, especially humans and their companion animals, but has not been verified in other taxa1,3,4. Here, through field observation and experiments, we demonstrate that female concave-eared torrent frogs (Odorrana tormota), which inhabit noisy streams, use eyeblinks to communicate with males to urge them to initiate amplexus for mating. Our findings reveal that eyeblinks may serve as a social signal in non-primate species.

Listening Effort, An Overview of App Validation and Testing by the Audiology 4 all Project.

OBJECTIVE: To describe an application's development and validation process that aims to track hearing difficulties in adverse environments (a listening effort application). DESIGN: 71 subjects were evaluated, divided into two groups: 30 subjects aged between 18 and 30, and 41 subjects aged between 40 and 65. All subjects had European Portuguese as their native language; the Montreal Cognitive Assessment (MOCA) scored above 24, and all could read and write. All subjects performed the intelligibility test in noise and the test of listening effort. The two tests were randomly applied in the free field in the audiometric cabin and the application. RESULTS: There were no statistically significant differences between the results of the two methods (p>0.05). For the group aged between 40 and 65 years old, the ROC curve showed that intelligibility inferior to 68.5% and the number of correct answers lower than 1,5 in the listening effort test are the optimal cut-off for referral to further management. Both tests showed low sensitivity and specificity regarding individuals between 18 and 30 years old, indicating that the application is inappropriate for this age group. CONCLUSIONS: The application is valid and can contribute to the screening and self-awareness of listening difficulties in middle age, with a reduction in the prevalence of dementia soon.

A frequency peak at 3.1 kHz obtained from the spectral analysis of the cochlear implant electrocochleography noise.

INTRODUCTION: The functional evaluation of auditory-nerve activity in spontaneous conditions has remained elusive in humans. In animals, the frequency analysis of the round-window electrical noise recorded by means of electrocochleography yields a frequency peak at around 900 to 1000 Hz, which has been proposed to reflect auditory-nerve spontaneous activity. Here, we studied the spectral components of the electrical noise obtained from cochlear implant electrocochleography in humans. METHODS: We recruited adult cochlear implant recipients from the Clinical Hospital of the Universidad de Chile, between the years 2021 and 2022. We used the AIM System from Advanced Bionics® to obtain single trial electrocochleography signals from the most apical electrode in cochlear implant users. We performed a protocol to study spontaneous activity and auditory responses to 0.5 and 2 kHz tones. RESULTS: Twenty subjects including 12 females, with a mean age of 57.9 ± 12.6 years (range between 36 and 78 years) were recruited. The electrical noise of the single trial cochlear implant electrocochleography signal yielded a reliable peak at 3.1 kHz in 55% of the cases (11 out of 20 subjects), while an oscillatory pattern that masked the spectrum was observed in seven cases. In the other two cases, the single-trial noise was not classifiable. Auditory stimulation at 0.5 kHz and 2.0 kHz did not change the amplitude of the 3.1 kHz frequency peak. CONCLUSION: We found two main types of noise patterns in the frequency analysis of the single-trial noise from cochlear implant electrocochleography, including a peak at 3.1 kHz that might reflect auditory-nerve spontaneous activity, while the oscillatory pattern probably corresponds to an artifact.

Automated Speech Audiometry: Can It Work Using Open-Source Pre-Trained Kaldi-NL Automatic Speech Recognition?

A practical speech audiometry tool is the digits-in-noise (DIN) test for hearing screening of populations of varying ages and hearing status. The test is usually conducted by a human supervisor (e.g., clinician), who scores the responses spoken by the listener, or online, where software scores the responses entered by the listener. The test has 24-digit triplets presented in an adaptive staircase procedure, resulting in a speech reception threshold (SRT). We propose an alternative automated DIN test setup that can evaluate spoken responses whilst conducted without a human supervisor, using the open-source automatic speech recognition toolkit, Kaldi-NL. Thirty self-reported normal-hearing Dutch adults (19-64 years) completed one DIN + Kaldi-NL test. Their spoken responses were recorded and used for evaluating the transcript of decoded responses by Kaldi-NL. Study 1 evaluated the Kaldi-NL performance through its word error rate (WER), percentage of summed decoding errors regarding only digits found in the transcript compared to the total number of digits present in the spoken responses. Average WER across participants was 5.0% (range 0-48%, SD = 8.8%), with average decoding errors in three triplets per participant. Study 2 analyzed the effect that triplets with decoding errors from Kaldi-NL had on the DIN test output (SRT), using bootstrapping simulations. Previous research indicated 0.70 dB as the typical within-subject SRT variability for normal-hearing adults. Study 2 showed that up to four triplets with decoding errors produce SRT variations within this range, suggesting that our proposed setup could be feasible for clinical applications.