Ear Science Institute Australia

ABSTRACT Meniere disease (MD) is an inner ear disorder characterized by episodic vertigo, tinnitus, fluctuating sensorineural hearing loss (SNHL), and aural fullness. Its hallmark pathological feature is endolymphatic hydrops. MD shows significant familial clustering in European and East Asian populations, supporting a strong genetic component in disease susceptibility. Dysfunctional sensory epithelia, particularly in the cochlea and vestibular organs, are increasingly recognized as central to the development of SNHL in MD patients. Notably, numerous non‐syndromic hearing loss genes such as OTOG, MYO7A, TECTA, or TRIOBP are expressed in sensory epithelial cells across the inner ear, including hair cells and supporting cells. Rare variants in these MD‐associated genes may contribute to MD pathogenesis through disruption of hair cell stereocilia, interfering mechanoelectrical transduction, disturbing ionic homeostasis, or affecting inner ear development. This review aims to summarize the current evidence on SNHL genes expressed in the inner ear sensory epithelium and their potential role in the molecular pathophysiology of MD.

Mouse models are relevant to study functionality of genes involved in human hearing and vestibular disorders; however, other pre-clinical models including organoids could be more suitable depending on the gene and its homology across species. While some mouse models replicate human hearing phenotypes, models for vestibular disorders like Meniere Disease (MD) are lacking. We aimed to identify genes associated with auditory and vestibular phenotypes (AVP) in humans and mice to prioritize candidate genes for further MD research. A systematic review was conducted extracting data from PubMed, Scopus, the International Mouse Phenotyping Consortium (IMPC), and the Deafness Variation Database (DVD). We included studies reporting AVP linked to genetic variants in human, mice or both. A total of 31 interspecies auditory phenotype genes shared between the IMPC and DVD, of which 25 were expressed in both cochlear and vestibular tissues. Five were prioritized as AVP candidates—CIB2, COL9A2, CLRN1, GRXCR1, MARVELD2. IMPC screening also revealed 52 mouse hearing loss genes, several with strong cochlear and vestibular expression not previously described. Integrating phenotypic and expression data highlighted NIN, CCDC88C, OTOG, CLRN1, GRXCR1, and MARVELD2 as promising candidates for MD. Vestibular phenotyping is underrepresented in current KO mouse models, as vestibular function is not systematically tested in the IMPC pipeline, leading to incomplete annotation of vestibular phenotypes. Comprehensive vestibular assessments in IMPC pipelines and targeted vestibular phenotype evaluation of individuals with rare variants in DVD genes are essential to advance translational vestibular research.

Objectives: To report the number of cochlear implantation procedures and recipients in Australia since 2000 by age, and to estimate the adult uptake of cochlear implants. Methods: This was a retrospective analysis of data, using publicly available data on private and public hospital procedures undertaken in Australia between 2000/01 and 2022/23. The main outcome measures were: (i) Number of cochlear implants per financial year, by paediatric, adults, or 10-year age groups, and population adjusted. (ii) Adult uptake rate of cochlear implants, adjusted for explantation and replantation rates, and bilateral implantation rates. This study followed STROBE guidelines for reporting. Results: 25,611 devices were implanted between July 2000 and June 2023, with annual numbers rising from 200 per year to over 1400 per year. Despite females have a 50% lower prevalence of hearing loss than males, approximately equal number of males and females are implanted. Paediatric implantation has declined since 2016. Adult uptake rate of cochlear implants is estimated to be 10.5%. Conclusions: Despite the known economic and social benefits of cochlear implants, and the rising number of people with hearing loss, the initial increase in rates of implantation appeared to have slowed, and the uptake rate remains low. Public health and hospital policy should be directed to improving public education, awareness, and referral and assessment pathways, especially for males.

Objective This study aimed to identify ear and hearing healthcare professionals’ current knowledge, attitudes, and practices in caring for people with cognitive impairment and dementia in China. Design A cross-sectional survey was distributed to eligible ear and hearing professionals in China. Knowledge, attitudes, and practices were compared among demographic factors. Linear regression assessed association between demographic information and survey responses. Structural equation model was used to identify mediation effects between knowledge, attitudes, and practices. Study sample 334 ear and hearing healthcare professionals. Results Respondents showed high knowledge and positive attitude towards providing ear and hearing care to patients with potential cognitive impairment, but lower practice scores. Multiple regression analysis showed that professional role significantly influenced practice behaviors. Mediation analysis demonstrated that around 25% of the effect of knowledge on practice was mediated by attitude. Conclusion This study found significant differences between knowledge, attitudes, and practice among Chinese ear and hearing professionals regarding cognitive impairment and hearing loss. There is a need for practice guidelines and training to enhance care for patients with comorbid hearing and cognitive impairments. Addressing the knowledge–practice gap will also require system-level supports, including multidisciplinary referral pathways and closer integration of hearing and cognitive health services.

Research on the association between hearing loss and cognition has primarily focused on speech-range hearing frequencies (i.e., 0.5-4 kHz), as these frequencies are most relevant to everyday functioning. However, age-related hearing loss (ARHL) tends to impact higher-frequency hearing first, and more severely. Despite this, limited research has investigated the relationship between high-frequency (i.e., >4 kHz) hearing loss and cognitive impairment. In the current study, we aimed to assess whether high-frequency hearing loss predicts non-verbal cognitive functions (i.e., visuospatial executive function, learning, and memory tasks) above and beyond speech-frequency hearing loss. Participants were 241 English-speaking adults, aged 40-88 years, with hearing loss. Audiometrically assessed better-ear, speech-frequency (0.5, 1, 2 & 4 kHz; BE4PTA) and high-frequency (6 & 8 kHz; BE2PTA) hearing loss were compared to cognitive functions measured using non-verbal tests from the Cambridge Neuropsychological Test Automated Battery; covariates included hearing-loss asymmetry, age, sex, premorbid IQ, and mental health measured with the short-form Depression Anxiety Stress Scales. While correlation analyses demonstrated that all measured cognitive faculties were associated with both BE4PTA and BE2PTA, hierarchical linear regression analyses demonstrated that only BE4PTA predicted cognitive flexibility and working-memory ability after controlling for covariates; age primarily accounted for BE2PTA's cognitive effects. While both speech and higher-frequency hearing loss were associated with poorer cognition, only the former demonstrated effects beyond those of ageing. However, the present study only investigated two frequencies in the higher range, encouraging broader investigation of higher-frequency hearing's cognitive effects in the future.

Implantation of ClearDrum ® , a biodegradable silk fibroin device, into the middle ear (ME) cavity in a rat model will not affect hearing thresholds as measured by auditory brainstem response. Chronic otitis media (COM) is a recurrent middle ear infection often accompanied by tympanic membrane perforation. Our laboratory has developed a biodegradable silk fibroin device (ClearDrum®) designed to treat tympanic membrane perforations in COM. ClearDrum ® acts as a prosthetic eardrum, providing a substrate on which tympanic membrane cells can grow and acts as a long-lasting implant. Two formulations were tested based on silk/glycerol and silk/polyurethane blends. Animals were anesthetized, and either a ClearDrum ® formulation or an autologous cartilage graft was surgically implanted into the middle ear. Thresholds of the auditory brainstem response (ABR) were measured at the time of implantation and at 4 and 12 weeks post-implantation to assess hearing after the implantation. After the final measurements at 12 weeks, middle ear and cochlea were harvested for histological assessment. No significant differences in ABR thresholds between male and female animals were found at any timepoint. Results showed that there were no detrimental effects of either Cleardrum ® formulation on ABR thresholds as compared with implantation of autologous cartilage and no presence of inflammation within the middle ear or cochlea. Our ABR data suggest no substantial ototoxic effects on outer or inner hair cells and provides some support toward clinical translation of ClearDrum devices.

ObjectiveTo compare hearing preservation outcomes between lateral wall and perimodiolar electrode arrays for cochlear implant patients.Study DesignRetrospective cohort study.SettingA large Western Australian cochlear implant clinicMethodsA total of 311 adult cochlear implant recipients (321 ears) implanted between 2017 and 2022 were included. Of these, 174 presented with postlingual hearing loss and preoperative functional low-frequency hearing. The change in low-frequency pure-tone average was assessed as the difference between preoperative to 3-, 6-, and 12-months postoperative measurements. Data were analyzed through linear mixed-effects modeling and one-way ANOVA.ResultsPreoperative low-frequency, pure-tone average was higher for those implanted with perimodiolar compared with lateral wall electrodes (P < .05). The linear mixed-effects model revealed that change in low-frequency pure-tone average at all postoperative timepoints was similar between lateral wall and perimodiolar electrodes (P > .05).ConclusionThere were similar changes in residual postoperative hearing between all electrode types when controlling for preoperative low-frequency hearing and age implanted. These data suggest that newer, thinner perimodiolar and lateral wall electrodes could be considered for individuals with greater levels of preoperative low-frequency hearing.

The control of slag foaming is important for optimising basic oxygen furnace (BOF) performance. Acoustics systems monitoring wide frequency bandwidths have been applied to BOF monitoring for the purpose of understanding slag foam height and density but there is limited information about their accuracy and repeatability. Improved understanding of the fundamental behaviour of sound in slag foam could help resolve these issues. In this cold physical model study using, aqueous foams generated in a cylindrical vessel were used to study the attenuation of sound in large samples of foam. Sound pulses over the range of 201 to 1801 Hz were transmitted through varying aqueous foam heights of 100 to 250 mm and acoustic signals detected via a measurement microphone were analysed. The results indicated aqueous foams consisting of smaller bubbles in the range of 0.4 to 0.75 mm with visibly thicker outer films displayed a stronger correlation between the attenuated sound and the stationary foam heights. It was also observed that frequencies above 1009 Hz were more sensitive in terms of their attenuation in varying foam heights and the time-dependant drainage of bubbles compared to lower frequencies. These frequencies were generally higher than those used for industrial slag foam monitoring systems.

Objective To examine help-seeker satisfaction with the first communication of a tinnitus diagnosis by a healthcare provider, whether help-seekers undertook treatment and how they rated this treatment. Design A survey design assessed tinnitus characteristics and distress, health status, help-seeking, diagnosis communication, treatment and patient satisfaction. Study sample A self-selected cohort and a population-based cohort. Results Satisfaction scores were examined against demographic, clinical factors, and type of healthcare provider. A total of 281 adults participated (median age 61.6, IQR = 10.8 years), 52.3% sought help for tinnitus and 22.4% received treatment. The most frequently seen healthcare providers were general practitioners (34.0%), audiologists (29.3%) and ear, nose and throat specialists (25.9%). About two-thirds (64.1%) of help-seekers were unsatisfied with the first communication of a tinnitus diagnosis they received, and 56.5% rated their first tinnitus treatment as poor. Help-seekers were significantly more satisfied with audiologists than other providers regarding the communication of the first tinnitus diagnosis. Higher tinnitus distress scores were significantly associated with lower patient satisfaction with communication of first tinnitus diagnosis. No other factors were associated with patient satisfaction. Conclusion There are significant communication barriers along the tinnitus clinical pathway. Identifying and addressing these barriers could improve patient satisfaction.