Normal Hearing Research Articles

Development and verification of non-supervised smartphone-based methods for assessing pure-tone thresholds and loudness perception

Objective The benefit of using smartphones for hearing tests in a non-supervised, rapid, and contactless way has drawn a lot of interest, especially if supra-threshold measures are assessed that go beyond audiogram-based measures alone. It is unclear, nevertheless, how well these measures compare to more supervised and regulated manual audiometric assessments. The aim of this study is to validate such smartphone-based methods against standardised laboratory assessments. Design Pure-tone audiometry and categorical loudness scaling (CLS) were used. Three conditions with varying degrees of supervision were created and compared. In order to assess binaural and spectral loudness summation, both narrowband monaural and broadband binaural noise have been examined as CLS test stimuli. Study sample N = 21 individuals with normal hearing and N = 16 participants with mild-to-moderate hearing loss. Results The tests conducted here did not show any distinctions between smartphone-based and laboratory-based methods. Conclusions Non-supervised listening tests via smartphone may serve as a valid, reliable, and cost-effective approach, e.g. for pure-tone audiometry, CLS, and the evaluation of binaural and spectral loudness summation. In addition, the supra-threshold tests can be constructed to be invariant against missing calibration and external noise which makes them more robust for smartphone usage than audiogram measures.

Sex-specific age-related changes in excitatory and inhibitory intra-cortical circuits in mouse primary auditory cortex.

A common impairment in aging is age-related hearing loss (presbycusis), which manifests as impaired spectrotemporal processing. Presbycusis can be caused by a dysfunction of the peripheral and central auditory system and these dysfunctions might differ between the sexes. To date, the circuit mechanisms in the central nervous system responsible for age-related auditory dysfunction remain mostly unknown. In the auditory cortex (ACtx), aging is accompanied by alteration in normal inhibitory (GABA) neurotransmission and changes in excitatory (NMDA and AMPA) synapses, but which circuits are affected has been unclear. Here we investigated how auditory cortical microcircuits change with age and if sex-dependent differences existed. We performed laser-scanning photostimulation (LSPS) combined with whole-cell patch clamp recordings from Layer (L) 2/3 cells in primary auditory cortex (A1) in young adult (2-3 months) and aged (older than 18 months) male and female CBA/CaJ mice which have normal peripheral hearing. We found that L2/3 cells in aged male animals display functional hypoconnectivity of inhibitory circuits originating from L2/3 and L4. Compared to cells from young adult mice, cells from aged male mice have weaker excitatory connections from L2/3. We also observed an increased diversity of excitatory and inhibitory inputs. These results suggest a sex-specific reduction and diversification in excitatory and inhibitory intralaminar cortical circuits in aged mice compared with young adult animals. We speculate that these unbalanced changes in cortical circuits contribute to the functional manifestations of age-related hearing loss in both males and females.Significance Statement A common impairment in aging is age-related hearing loss (presbycusis) which can be caused by a dysfunction of the peripheral and central auditory system. Impaired spectrotemporal processing in the auditory cortex is thought to underlie some of these impairments. We compare auditory cortex circuits in vitro in young adult (∼P60) and aged (∼P585) CBA mice. We find a sex-specific reduction in excitatory and inhibitory intralaminar cortical circuits in aged mice compared with young adult animals. We speculate that these unbalanced changes in cortical circuits underlie the differential functional manifestations of age-related hearing loss in both males and females.

Turkish mobile speech discrimination in real noise 4-word sentence test findings in individuals with hearing loss aged 8–12 years

BackgroundIn daily life, there has been a need to establish verbal communication with sentences instead of single-syllable words and to be tested with sentences that better reflect social life. In this study, it was aimed to evaluate signal noise ratio thresholds and speech comprehension scores in noise in children with severe sensorineural hearing loss by using real ambient noises, four-word spectral balanced sentences, and light, medium, and high input signal levels.ResultsA total of 40 children, including 20 children with severe sensorineural hearing loss, using bilateral hearing aids, (10.23 ± 1.64) and 20 children with normal hearing (9.25 ± 1.48), aged 8–12 years, were included in the study. The newly developed Turkish Mobile Sentence Test for Distinguish Speech in Real Noises was applied to the participants. This test is performed using spectral and coherence balanced 4-word sentences, at − 10 dB, − 5 dB, 0 dB, 5 dB, and 10 dB SNR thresholds and 40, 60, and 80 dB sound levels at shopping mall and amusement park. Children with hearing loss had higher signal noise ratio thresholds at all sound levels in shopping malls, amusement parks, and classroom environments, and their speech comprehension scores in noise were lower at these thresholds (p < 0.05).ConclusionsChildren with hearing loss aged 8–12 have difficulties in verbal communication, in real ambient noises, and in speech discrimination tests, even with 4-word sentences at mild, medium, and high levels of intensity, compared to children with normal hearing. Further studies evaluating hearing aid fitting settings with signal noise ratio thresholds are needed.

An Investigation of the Stiffness Characteristics of a PWR Nuclear Fuel Spacer Grid by a 3D Shell Model

The structural integrity of fuel assemblies hinges significantly on the effectiveness of spacer grids. In this paper, we introduce a novel approach to assess the structural robustness of the mid-spacer grid (SG) of the PLUS7 fuel assembly (FA) using 3D shell elements. Any excessive external load from seismic activity can be broken down into two perpendicular components, namely normal load and shear load. The decomposition enables easy assessment of the structural integrity of the fuel spacer grid for any external loads. From the analysis, the reaction force of normal input displacement is around 440 times greater than that for shear input displacement for the same amount of displacement. This result highlights how vulnerable the spacer grid is to shear load and this should be considered in studies of fuel assembly integrity assessment. This study also highlights the need for improved and more robust spacer grids for safer operation of NPPs.

A self-reported questionnaire for screening of hearing impairment in older

IntroductionHearing loss is a prevalent concern for older adults aged 60 years and above, making early intervention essential. Accurate diagnosis relies on calibrated instruments, soundproof environments, and qualified audiologists. While these resources are often available, certain situations may limit access. This study investigates the potential of self-assessment tools as an alternative screening method for older adults to identify those who may require further audiological evaluation.AimTo study the efficacy of self-reported questionnaire in identifying hearing loss among older adults and its potential application in clinical practice.MethodThis cross-sectional study included a total of 160 older adults. Participants were divided into two groups: Group I with normal hearing sensitivity and Group II with mild to moderately severe sensorineural hearing loss. Pure-tone audiometry was used to measure hearing thresholds, followed by administering a questionnaire.ResultIt was observed that there was significant difference between scores of the self-awareness and communication difficulties for different degrees of hearing loss among older adults (p-value < 0.05). The cut-off score was observed to be increasing with the increase of the hearing loss, and also, it was observed that there is a positive strong correlation between scores of self-awareness domain and communication difficulties domain across different degrees of hearing loss.ConclusionThus, this questionnaire could be an effective tool for screening of hearing loss and assessing its severity, from mild to moderately severe in older adults. This will facilitate early detection and intervention, potentially enhancing their quality of life.

Evaluation of the montreal cognitive assessment in idiopathic tinnitus patients with mild hearing loss

Objective:To explore the effect of mild hearing loss on cognitive function by evaluating the Montreal Cognitive Assessment（MoCA） in idiopathic tinnitus patients with mild hearing loss. Methods:102 patients with idiopathic tinnitus（68 patients with normal hearing and 34 patients with mild hearing loss） whose first complaint is tinnitus and 34 healthy volunteers（control group） were included. All subjects were asked to fill the MoCA, Tinnitus Handicap Inventory（THI）, Self-rating Anxiety Scale（SAS）, Self-rating Depression Scale（SDS）, and Pittsburgh Sleep Index（PQSI） after collecting medical history, pure tone audiometry, tinnitus matching and masking test. The clinical characteristics and scores of each scale were compared among the groups. Results:The score and each dimension score of MoCA in idiopathic tinnitus patients with normal hearing were significantly lower than the normal population（P<0.05）; compared with patients with idiopathic tinnitus with normal hearing, patients with mild hearing loss were older（P<0.01） and had lower MoCA scores（P<0.05）. There was no significant difference in MoCA scores（P>0.05） between tinnitus patients with normal hearing and mild hearing loss after correcting confounding factors（age, gender, years of education, duration of tinnitus, frequency of tinnitus tones, side of tinnitus, THI score, SAS score, SDS score, and PQSI score）; idiopathic tinnitus patients with mild hearing loss scored significantly lower in attention and working memory dimensions than idiopathic tinnitus patients with normal hearing（P<0.01）. Conclusion:Patients with idiopathic tinnitus may have cognitive dysfunction, and mild hearing loss may not be a factor that promotes the further aggravation of cognitive dysfunction in patients with idiopathic tinnitus. The role of hearing loss in cognitive dysfunction in patients with idiopathic tinnitus needs further research.

Perception of voice cues and speech-in-speech by children with prelingual single-sided deafness and a cochlear implant

Voice cues, such as fundamental frequency (F0) and vocal tract length (VTL), help listeners identify the speaker's gender, perceive the linguistic and emotional prosody, and segregate competing talkers. Postlingually implanted adult cochlear implant (CI) users seem to have difficulty in perceiving and making use of voice cues, especially of VTL. Early implanted child CI users, in contrast, perceive and make use of both voice cues better than CI adults, and in patterns similar to their peers with normal hearing (NH).In our study, we investigated the perception and use of voice cues in children with single-sided deafness (SSD) who received their CI at an early age (SSD+CI), in an attempt to bridge the gap between these two groups. The SSD+CI children have access to bilateral auditory information and often receive their CI at an early age, similar to CI children. They may also have dominant acoustic representations, similar to CI adults who acquired hearing loss at a later age. As such, the current study aimed to investigate the perception and use of voice cues by a group of nine early-implanted children with prelingual SSD. The study consisted of three experiments: F0 and VTL discrimination, voice gender categorization, and speech-in-speech perception. In each experiment, the results of the SSD group are compared to children and adults with CIs (for their CI ear) and with typical hearing (for their NH ear).Overall, the SSD+CI children had poorer VTL detection thresholds with their CI compared to their NH ear, while their F0 perception was similar across ears. Detection thresholds for both F0 and VTL with their CI ear was comparable to those of bilaterally implanted CI children, suggesting that SSD+CI children do not only rely on their NH ear, but actually make use of their CI. SSD+CI children relied more heavily on F0 cues than on VTL cues for voice gender categorization, with cue weighting patterns comparable to those of CI adults. In contrast to CI children, the SSD+CI children showed limited speech perception benefit based on F0 and VTL differences between the target and masker speaker, which again corresponded to the results of CI adults. Altogether, the SSD+CI children make good use of their CI, despite a good-hearing ear, however, the perceptual patterns seem to fall in-between those of CI children and CI adults. Perhaps a combination of childhood neuroplasticity, limited experience with relying only on the CI, and a dominant acoustic representation of voice gender explain these results.

Evaluation of the immature granulocyte count in idiopathic sudden sensorineural hearing loss

Aims: The purpose of our study was to show whether the immature granulocyte count (IGC) can be used as a prognostic marker in idiopathic sudden sensorineural hearing loss (ISSNHL). Methods: This study is a retrospective case-control clinical study. Patients presenting to our clinic between June 2019 and June 2022, diagnosed with ISSNHL, and receiving the same treatment protocol were investigated. Preoperative complete blood count values of 40 normal individuals with normal hearing who presented to our clinic due to nasal septum deviation were adopted as the control group. Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) (platelet × neutrophil / lymphocyte) values were calculated in addition to IGC values in complete blood counts from the patient and control groups. The patient group was classified into treatment-responsive and non-responsive subgroups according to the results of audiological examinations performed after one month based on Siegel’s criteria. IGC, SII, NRL, and PLT values were compared between all groups. Results: Comparison of the patient and control group’s complete blood count data revealed higher leukocyte and neutrophil counts, IGC and also NLR, PLR, and SII values in the patient group compared to the control group. However, lymphocyte counts were lower in the patient group. None of the parameters previously emerging as significant in the data of patients with healing and non-healing idiopathic sudden hearing loss were statistically significant, and IGC is of no prognostic value in ISSNHL. Conclusion: IGC may be a novel and inexpensive indicator of ISSNHL and one easily determined with complete blood count, but it is of no prognostic value in the disease.

Clinical hearing phenotypes analysis of GJB2 gene p.V37I homozygote and compound heterozygote mutation in infants

Objective:To analyze the hearing phenotypes of p. V37I homozygote and compound heterozygote mutation in GJB2 gene, and to provide basis for genetic counseling. Methods:Fifty-three subjects with p. V37I homozygote and compound heterozygote mutation were recruited at Department of Otolaryngology Head and Neck Surgery, Beijing Tongren Hospital from January 2023 to March 2024. All subjects received universal newborn hearing screening（UNHS）, 23-site chip neonatal deafness genetic screening and audiological tests, including ABR, acoustic immittance, DPOAE, ASSR. The results of newborn hearing screening and hearing diagnosis were compared between homozygous mutation group of 30 cases and compound heterozygous mutation group of 23 cases. Results:In 53 cases, the overall refer rate of UNHS was 64.15%（34/53）, the refer rate of homozygous mutation group was 80.00%（24/30）, which was higher than that of compound heterozygous mutation group（43.48%, 10/23）, the difference between the two groups was statistically significant（P<0.05）. Three subjects with p. V37I compound heterozygous mutation had passed UNHS and diagnosed with unilateral mild hearing loss. The average age of diagnosis of 53 cases was （3.77±1.40） months, 25 cases with hearing loss accounted for 47.17%, including 13 cases with unilateral, 12 cases with bilateral, 28 cases with normal hearing accounted for 52.83%. There was no significant difference between homozygous mutation group（56.67%, 17/30） and compound heterozygous mutation group（34.78%, 8/23） in the proportion of confirmed hearing loss（P>0.05）. Among 37 ears of 25 patients with hearing loss, the proportion of mild, moderate and profound hearing loss were 70.27%（26/37）, 27.03%（10/37） and 2.70%（1/37）, respectively. The hearing loss degree of the homozygous mutation group and the compound heterozygous mutation group were mainly mild, accounting for 70.37%（19/27） and 70.00%（7/10） respectively. There was no significant difference between the two groups in the distribution of hearing loss degree（P>0.05）. Conclusion:The probability of hearing loss was 47.17% in infants of GJB2 gene p. V37I homozygote and compound heterozygote mutation, mainly mild hearing loss. There was no difference in the probability of hearing loss and the distribution of hearing loss degree between the two groups. Patients with p. V37I homozygous and compound heterozygous mutation currently diagnosed as normal hearing need continuous clinical follow-up.

Silicone-based AC102-loaded cochlear implant coatings protect residual hearing in an animal model of cochlear implantation

Cochlear implant users with residual hearing benefit synergistically from combined electrical stimulation via the cochlear implant and preserved residual hearing after surgery. However, direct mechanical trauma and subsequent inflammation may deteriorate hearing function. AC102, a novel otoprotective pyridoindole with anti-apoptotic and anti-oxidative properties significantly improved hearing recovery following cochlear implantation when administered intratympanically prior to surgery. Additionally, AC102 exerts neurotrophic effects, possibly aiding in the preservation of auditory nerve fibers and spiral ganglion neurons. Rapid clearance of the drug, however, might be a limiting factor to further attenuate the inflammatory response and maintain neuronal health. The aim of the current study was to design an AC102-loaded electrode array for sustained drug delivery and investigate its effects in hearing preservation cochlear implantation.First, the release-kinetics of AC102 were investigated in vitro and modelled by the Higuchi equation of drug release. An electrode array coated with 10% AC102 was manufactured, its release kinetics evaluated, and subsequently tested in vivo. 20 normal hearing Mongolian gerbils were unilaterally implanted with an AC102-loaded or an unloaded control electrode. Compound action potentials were measured prior to cochlear implantation and serially over 28 days. Hair cells, inner hair cell synapses, and auditory nerve fibers were quantified in cochlear whole-mounts by immunofluorescence staining.AC102 release from silicone coating could be predictably modelled by the Higuchi equation of drug release. The electrode array with an AC102-silicone depot enabled non-linear sustained drug release with initially higher release concentrations. In vivo, the AC102-loaded electrode array significantly recovered auditory threshold shifts near the maximum insertion depth over 28 days. In the apical region, a significant recovery was noticed only until day 14, after which threshold shifts aligned between groups. Histologically, AC102-loaded electrodes significantly preserved outer hair cells apical of the maximum insertion depth and inner hair cells and neuronal structures at the tip of the inserted electrode.In conclusion, the drug-loaded electrode arrays could predictably release AC102 over a period of 28 days. AC102 enabled the restoration of auditory thresholds near the area of maximum insertion, which is the desired region to be preserved in cochlear implant recipients with residual hearing.

Ensemble responses of auditory midbrain neurons in the cat to speech stimuli at different signal-to-noise ratios

Originally reserved for those who are profoundly deaf, cochlear implantation is now common for people with partial hearing loss, particularly when combined with a hearing aid. This combined intervention enhances speech comprehension and sound quality when compared to electrical stimulation alone, particularly in noisy environments, but the physiological basis for the benefits is not well understood. Our long-term aim is to elucidate the underlying physiological mechanisms of this improvement, and as a first step in this process, we have investigated in normal hearing cats, the degree to which the patterns of neural activity evoked in the inferior colliculus (IC) by speech sounds in various levels of noise allows discrimination between those sounds. Neuronal responses were recorded simultaneously from 32 sites across the tonotopic axis of the IC in anaesthetised normal hearing cats (n=7). Speech sounds were presented at 20, 40 and 60dB SPL in quiet and with increasing levels of additive noise (signal-to-noise ratios (SNRs) –20, –15, –10, –5, 0, +5, +10, +15, +20dB). Neural discrimination was assessed using a Euclidean measure of distance between neural responses, resulting in a function reflecting speech sound differentiation across various SNRs. Responses of IC neurons reliably encoded the speech stimuli when presented in quiet, with optimal performance when an analysis bin-width of 5-10ms was used. Discrimination thresholds did not depend on stimulus level and were best for shorter analysis binwidths. This study sheds light on how the auditory midbrain represents speech sounds and provides baseline data with which responses to electro-acoustic speech sounds in partially deafened animals can be compared.

The Influence of Vowels on the Identification of Spoken Disyllabic Words in the Malayalam Language for Individuals with Hearing Loss

Background/Objectives: The present study investigates the reasons for better recognition of disyllabic words in Malayalam among individuals with hearing loss. This research was conducted in three experiments. Experiment 1 measured the psychometric properties (slope, intercept, and maximum scores) of disyllabic wordlists. Experiment 2 examined PBmax scores across varying degrees of sensorineural hearing loss (SNHL) and compared these findings with studies in other Indian and global languages. Experiment 3 analyzed the recognition performance of different vowel combinations across varying degrees of hearing loss. Methods: Experiment 1: Psychometric functions for disyllabic word recognition were derived from 45 individuals with normal hearing. Word recognition was tested in quiet at nine hearing levels ranging from −10 to +40 dB HL. Experiment 2: 1000 participants with SNHL were categorized by hearing loss severity (mild, moderate, moderately severe, severe, and profound). Word recognition scores, including PBmax, were analyzed and compared across severity levels. Experiment 3: Percent error scores for 17 vowel combinations were assessed in 37 participants with SNHL. Ten disyllabic words represented each combination. Results: Disyllabic wordlists showed significantly higher word recognition scores than monosyllabic lists across all degrees of hearing loss. Individuals with mild-to-moderately severe SNHL achieved higher PBmax scores, with performance declining at severe- and profound-loss levels. The higher recognition of disyllabic words was attributed to contextual cues and low-frequency vowel-based information, particularly benefiting those with residual low-frequency hearing. Error analysis highlighted the influence of specific vowel combinations on word recognition performance. Conclusions: Disyllabic words are easier to recognize than monosyllabic words for individuals with SNHL due to their rich contextual and low-frequency energy cues. Disyllabic wordlists sustain higher recognition scores up to moderately severe hearing loss but show a marked decline with more severe losses. The phonemic balance of wordlists and vowel combinations significantly influences word recognition, emphasizing the importance of these factors in developing wordlists for clinical use.

Brainwave entrainment using binaural beats stimulation: Exploring the treatment efficacy in individuals with tinnitus having normal hearing sensitivity

ObjectiveThe study aimed to compare the efficacy of brainwave entrainment in the treatment of individuals with tinnitus having normal hearing sensitivity. The effect of binaural beats (BB) stimulation in reducing negative emotions and tinnitus handicap post-three months is explored in this longitudinal study. MethodThe study comprised sixty individuals (four groups) with tinnitus having normal hearing. The outcome measures of BB with beat frequencies falling under delta (4 Hz), theta (6 Hz), and alpha (10 Hz) and a standard tinnitus masker (white noise) were compared with the pre-treatment baseline scores for tinnitus handicap, depression, and stress levels, and quality of life parameters. ResultsAll four groups showed an improvement in tinnitus symptoms and negative emotions. However, the groups that received BB stimulation (I, II, III) showed a remarkable reduction in scores for the tinnitus handicap, depression, and stress levels and an increase in quality-of-life scores for the domains that assessed physical and psychological health when compared to the group IV who received standard tinnitus masker. ConclusionIt was observed that all three broadband (BB) stimuli were equally effective in treating tinnitus handicap symptoms. However, the results cannot be definitively attributed to brainwave entrainment, as they may also reflect the effects of sound therapy. Additionally, the lack of significant differences among the BB frequencies suggests that the benefits may not arise specifically from brainwave entrainment, especially without a comparison to beta frequency BB. This technique should be adopted into clinical practice with generalizability after further research on a randomized sample.

Recovery of hearing loss in atypical Meniere’s disease after treatment with orofacial and neck massage: A case report

BACKGROUND A 48-year-old female presented with sudden-onset right-sided aural fullness, low-frequency hearing loss, and tinnitus. Medical history included right-sided temporomandibular joint disorder (TMJD) with crepitation, and retro-orbital headaches. The patient was diagnosed with atypical Meniere’s disease (MD) and received intratympanic steroids, prednisone, betahistine, and began a low-sodium diet; however, the patient’s symptoms worsened. CASE SUMMARY The patient sought physical therapy for TMJD; testing revealed reduced motion and dysfunction with vertical opening, lateral excursion of the mandible to the right, and tenderness to palpation. Treatment included soft tissue mobilization of right facial structures and temporal fossa, intraoral massage of the right pterygoid musculature, and massage of right neck structures. After 4 weeks, the patient noticed subjective improvement in hearing and decreased headaches. After 11 weeks, an audiogram showed that the hearing loss had recovered. The patient has continued the daily at-home intraoral/neck massage therapy and maintained normal hearing over 4 years to date. The temporal relationship between physical therapy and recovery of hearing loss suggests muscular or inflammatory etiology as at least partially causative of this patient’s symptoms. The mechanism of healing may have been due to decreased inflammation, improved blood flow, restored function of cranial nerves, or some combination of these and other unknown factors. CONCLUSION This report suggests that orofacial physical and massage therapy may be an effective treatment for the cochlear symptoms associated with MD.

Does Chronic Subjective Tinnitus Affect Cognitive Performance In Adults with Hearing Thresholds of 25 dB and Less Between 0.5-4 kHz.

In literature, the cognitive performance results of normal hearing individuals with tinnitus are inconsistent. It also differs in the control of other factors that may affect cognition. This study aimed to determine the differences in attention and memory performance between normal hearing individuals with chronic subjective tinnitus and age-sex-education-matched healthy controls. Normal hearing individuals with subjective chronic tinnitus between 18 and 55 years of age, who have normal cognitive abilities (tinnitus group, n = 30) and age-sex-matched normal hearing individuals without tinnitus who have normal cognitive abilities (control group, n = 30) were included in this study. The Montreal Cognitive Assessment Test measured participants' general cognitive screening, and depressive symptoms were measured by Beck Depression Inventory (BDI). Tinnitus Handicap Inventory was used to determine the tinnitus handicap levels. Attention performance was evaluated with Stroop Test-TBAG Form, and short-term and working memory performances were evaluated with the Wechsler Adult Intelligence Scale-Revised (WAIS-R)-Digit Span Test. The tinnitus and control groups' depressive symptom scores were similar concerning the BDI (p = 0.90). There was no statistically significant difference between both groups according to the completion time of the five sections of the Stroop Test, the number of errors and corrections of the Stroop 5 test, and the (WAIS-R)-Digit Span Test scores (p > 0.05). In our study, the Stroop Test and Digit Span Test performances of individuals with tinnitus and normal hearing were similar to the control group. Despite previous studies claiming an effect of tinnitus on cognition, our contrary findings are discussed in the light of other demographic, audiological, and psychological measurement variables, especially hearing loss.

A Comparative Study of Auditory Processing and Working Memory Profiles in Young and Older Adults.

This study aimed to profile and compare the auditory processing and working memory skills of young and older adults with near-normal hearing thresholds (up to 2000 Hz) and cognition. This was done to investigate the effect of aging on these skills despite exhibiting near-normal peripheral hearing in low frequencies and normal cognitive skills. Twenty-five young adults (18 to 35 years) and 35 older adults (56 to 79 years) were recruited for the study. They were screened for near-normal hearing thresholds (up to 2000 Hz) as well as cognition, and written informed consent was obtained. A battery of auditory processing and working memory tests were administered to the participants. The responses obtained were compared using the Mann-Whitney U test. Principal component analysis (PCA) was also carried out to examine any relationship between the various auditory processes and the cognitive skills. The young adults had superior performance compared to older adults on most of the tasks. PCA revealed the influence of working memory on performance in most tests of auditory processing in young adults and to a lesser extent in older adults. This study aimed to assess and compare the auditory processing and working memory skills of young and older adults with normal hearing and cognition. Overall, young adults demonstrated superior performance compared to older adults across the tasks. The results of PCA indicated that the young adults utilized their cognitive resources better for auditory processing compared to the older adults. These findings suggest a need for tailored interventions targeting both auditory processing and working memory, especially among older adults, and highlight the importance of considering age-related differences in these cognitive processes when interpreting auditory processing assessments.

Longitudinal Effect of Music Exposure on Hearing Among Vocal Performance Students

The effects of music exposure on vocal performers remain relatively unknown. This study aimed to assess the immediate and long-term effects of music and singing practice on the peripheral auditory system of vocal performers using otoscopy, pure-tone audiometry, and noise dosimetry. The hearing status, sound pressure levels (SPLs), and sound doses of 12 vocal performers with normal hearing at the study’s onset were evaluated. Pre- and post-study questionnaires regarding the participants’ otologic health and music-making activities, as well as repeated hearing evaluations, were implemented. Additionally, noise dosimetry was conducted on each participant’s most vocally active day of the week. Audiometric assessments generally revealed normal hearing thresholds, with some exceptions. Half of the participants exhibited elevated low-frequency thresholds and over half of the participants displayed emerging audiometric “notches” at 6000 Hz. Noise dosimetry measurements indicated that most of the participants were consistently exposed to SPLs during music-making activities that exceeded recommended limits. Questionnaire responses highlighted that the participants often engaged in extra-curricular music-making activities, frequently with piano accompaniment, and with little to no use of hearing protection devices. A few of the participants reported histories of otologic issues and potential hearing problems.

Abnormal cochlear enhancement in Norrie disease.

Norrie disease (ND) is a rare x-linked disease with retinal and cochlear vascular abnormalities. Clinically, it is characterized by congenital blindness and progressive sensorineural hearing loss during adolescence. We present images of a 3year old child with ND and normal hearing demonstrating bilateral cochlear enhancement on brain MRI, a finding which has not been previously reported. ND mouse models show progressive degeneration of the endolymph-producing stria vascularis (SV); we hypothesize that these changes allow gadolinium leakage into the endolymph. Our images indicate that cochlear enhancement precedes changes in hearing and suggest that temporal bone/internal auditory canal MR imaging should be considered in the evaluation of ND. Future studies are needed to characterize the temporal evolution of this cochlear enhancement and how it corresponds with hearing loss. Mouse models suggest that it may be a transient phenomenon and diminish as the SV degenerates further. As ND gene therapy trials approach clinical use, cochlear enhancement could aid candidate selection and provide insight into treatment effect.

Sequential or simultaneous bilateral cochlear implantation: attention, memory, and language skills in children.

The effect of the inter-implant interval time on language and communication skills has been a subject of research for years in children with bilateral cochlear implants. This study aimed to investigate language and some attention and memory skills in children with bilateral sequential and simultaneous cochlear implants. The study included a total of 40 children aged between 6 and 8years old, grouping bilateral simultaneous cochlear implanted children, sequential implanted children with 0-2years interval, sequential implanted children with 2-4years interval, and normal hearing peers. The language skills of the children were assessed using the Test of Language Development: Primary 4th edition, their selective attention and coping skills with disruptive effect were evaluated using the Stroop test, sustained attention and visual-motor synchronization skills were assessed using the Cancellation Test, and short-term memory skills were evaluated using the Visual Auditory Digit Span Test. The findings were analyzed using nonparametric statistical methods, with a significance level set at 0.05. Children with bilateral simultaneous cochlear implants demonstrated better performance in language skills and the attention-related subtests of the Stroop test (p < 0.05). On the other hand, children with simultaneous and sequential cochlear implants achieved similar scores in the Cancellation and the Visual Auditory Digit Span Test (p > 0.05). Bilateral simultaneous cochlear implantation in children is beneficial for language, selective attention, and coping with the Stroop effect. However, these children may still lag behind their normal-hearing peers in terms of language, attention, and memory skills.

Cochlear origin of tinnitus and outer hair cell motor protein Prestin as a biomarker for tinnitus

Peripheral dysfunction and hearing loss are known risk factors for tinnitus; however, a portion of tinnitus patients exhibit no apparent peripheral auditory deficits. This article proposes that tinnitus may originate in the cochlea due to, undetectable damage to outer hair cells (OHCs) in individuals with normal hearing. The study further suggests that peripheral auditory deficits can be identified through the outer hair cell motor protein Prestin, which has potential as a biomarker for early detection. Minor OHC losses, which do not result in clinically detectable hearing loss, may lead to insufficient depolarization of inner hair cells (IHCs), thereby reducing sensory input along the cochlea-cortex pathway in the central auditory system. From a homeostatic gain control perspective, decreased amplification by OHCs, including abnormal electromotile responses, may lead to inadequate encoding by IHCs, contributing to the cochlear origin of tinnitus. Damage to OHCs that does not affect hearing thresholds, or abnormal electromotile contractions influenced by Prestin, may contribute to peripheral auditory dysfunction underlying tinnitus. As a result, pre-neural mismatched synchronization between OHCs and IHCs, driven by abnormal OHC electromotility, could cause sound processing disorders within the central auditory system. This pathophysiological mechanism at the cochlear level may lead to pathological alterations at multiple levels of the central auditory system. Prestin may serve as a potential biomarker for tinnitus, offering valuable insights into its cochlear origin and guiding future therapeutic developments.