Hearing Loss Disability Research Articles

Comparative analysis of mechanical characteristics of different topologies of the cantilever beam to mimic the function of the cochlea

According to the World Health Organization (WHO), approximately 5% of the world’s population has a hearing loss disability caused by various reasons. The cochlea is a spiral-shaped bone found in the inner ear that is capable of doing exceptional sound analysis, in terms of both frequency and intensity which allows the perception of sound frequency in the range of 20 Hz to 20 kHz. An artificial basilar membrane having various shapes has been developed but none of those covers the whole human audible frequency range. This paper compares the mechanical characteristics of the rectangular and taper piezoelectric cantilever to develop an artificial basilar membrane that mimics the human cochlea with high sensitivity. The cantilever beam is made up of molybdenum (Mo), aluminum nitride (AlN), tungsten (W) and the desired frequency range is obtained by varying the length and thickness of the cantilever beams. The 3D design and simulations were performed by COMSOL Multiphysics to study the Eigen frequency, displacement, and stress measurements of the cantilever. The Eigen frequency is observed to be increased with an increase in the thickness and decrease in the length for both rectangular and taper cantilever beam. The rectangular beam showed higher sensitivity and lower stresses compared to the taper beam. Therefore, the rectangular cantilever beam is more suitable to mimic the basilar membrane of the human cochlea.

Hearing testing in the U.S. Department of Defense: Potential impact on Veterans Affairs hearing loss disability awards

Hearing loss is the second most common disability awarded by the U.S. Department of Veterans Affairs (VA) to former members of the U.S. uniformed services. Hearing readiness and conservation practices differ among the four largest uniformed military services (Air Force, Army, Marine Corps, and Navy). Utilizing a data set consisting of all hearing loss claims submitted to the VA from fiscal years 2003–2013, we examined characteristics of veterans submitting claims within one year of separation from military service. Our results indicate that having a hearing loss disability claim granted was significantly more likely for men, individuals over the age of 26 years at the time of the claim, individuals most recently serving in the U.S. Army, and those with at least one hearing loss diagnosis. Importantly, individuals with at least one test record in the Defense Occupational and Environmental Health Readiness System-Hearing Conservation (DOEHRS-HC) system were significantly less likely to have a hearing loss disability claim granted by the VA. Within the DOEHRS-HC cohort, those with at least one threshold shift or clinical hearing loss diagnosis while on active duty were more than two and three times more likely to have a hearing loss disability claim granted, respectively. These findings indicate that an established history of reduced hearing ability while on active duty was associated with a significantly increased likelihood of an approved hearing loss disability claim relative to VA claims without such a history. Further, our results show a persistent decreased rate of hearing loss disability awards overall. These findings support increased inclusion of personnel in DoD hearing readiness and conservation programs to reduce VA hearing loss disability awards.

Noise-induced hearing loss: a military perspective.

To summarize relevant literature occurring over the past 12-18 months forwarding understanding of noise-induced hearing loss in relation to military service. Hearing loss prior to entry into military service is highly predictive of subsequent hearing loss and hearing loss disability. Tightly controlled organic solvent exposure may not be a significant risk factor for noise-induced hearing loss. Increasingly detailed analysis of high intensity noise, impulse and blast noise exposures, and the methods used to mitigate these exposures are leading to breakthroughs in understanding and predicting hearing loss in military service. Prevention, mitigation, treatment, and prediction of the effects of hazardous noise exposure in military service continue to require a multidisciplinary team of individuals from around the world fully aware of the detrimental effect to service members and their societies of hearing loss disability.

Pre-enlistment hearing loss and hearing loss disability among US soldiers and marines

Hearing loss is a common condition among US adults, with some evidence of increasing prevalence in young adults. Noise-induced hearing loss attributable to employment is a significant source of preventable morbidity world-wide. The US military population is largely comprised of young adult males serving in a wide variety of occupations, many in high noise-level conditions, at least episodically. To identify accession and service-related risk factors for hearing-related disability, matched case-control study of US military personnel was conducted. Individuals evaluated for hearing loss disability in the US Army and Marine Corps were frequency matched to controls without history of disability evaluation on service and enlistment year. Conditional logistic regression was used to examine the association between accession and service-related factors and hearing-related disability evaluations between October 2002 and September 2010. Individuals with medically disqualifying audiograms or hearing loss diagnoses at application for military service were 8 and 4 times more likely, respectively, to have a disability evaluation related to hearing loss, after controlling for relevant accession, demographic, and service-related factors. Conservative hearing loss thresholds on pre-enlistment audiograms, stricter hearing loss medical waiver policies or qualified baseline audiograms pre-enlistment are needed in the U.S military. Industrial corporations or labor unions may also benefit from identifying individuals with moderate hearing loss at the time of employment to ensure use of personal protective equipment and engineer controls of noise.

Long term hearing degeneration after platinum-based chemotherapy in childhood

The aim of this study was to investigate long-term development of hearing in subjects who had received platinum-based chemotherapy in childhood or adolescence. Another aim was to assess the self-reported hearing loss handicap and compare it to audiometric measurements. Medical records from individuals diagnosed with childhood cancer and treated with platinum-based chemotherapy between 1985 and 2000 at the University Hospital in Lund Sweden were reviewed retrospectively. Fifteen subjects, who fulfilled the eligibility criteria set for the study, underwent a thorough audiometric evaluation. The results show that the hearing loss, in subjects with ototoxicity had increased after the end of treatment, to include also the lower frequencies. The largest deterioration in hearing thresholds, up to 55 dB HL, was found at frequencies above 2 kHz. The findings also reveal that the subjects have a considerably greater hearing loss handicap and disability than would be expected from the results of the audiometric evaluations. The conclusion of this study is that children and adolescence treated with platinum-based chemotherapy should have regular audiometric follow-up examinations, also many years after the end of treatment. Furthermore, assessments of self-reported hearing disability should be made during and after chemotherapy.SumarioEl objetivo de este estudio fue investigar el desarrollo de la audición a largo plazo en sujetos que recibieron quimioterapia de platino en la niñez o en la adolescencia. Otro objetivo fue evaluar los auto-reportes de discapacidad por la pérdida auditiva y compararlos con las mediciones audiométricas. Se revisaron retrospectivamente los expedientes médicos de individuos diagnosticados con cáncer en la niñez y tratados con quimioterapia con platino entre 1985 y 2000, en el Hospital Universitario de Lund, Suecia. Quince sujetos que cubrieron los criterios de elegibilidad para el estudio, se sometieron a una evaluación audiométrica minuciosa. Los resultados mostraron que la pérdida auditiva en sujetos con ototoxicidad aumentó después de terminar el tratamiento, incluyendo también las frecuencias graves. La mayor pérdida en los umbrales auditivos, hasta de 55 dB HL, se encontró en las frecuencias superiores a 2 kHz. Los hallazgos revelan también que los sujetos presentan una discapacidad y una desventaja auditiva considerablemente mayor que lo que podría esperarse a partir de los resultados de las evaluaciones audiométricas. La conclusión de este estudio es que los niños y adolescentes tratados con quimioterapia con platino deben ser sometidos a un seguimiento en las evaluaciones audiométricas, incluso muchos años después de terminar el tratamiento. Más aún, las evaluaciones de los auto-reportes sobre discapacidad auditiva, deben practicarse durante y después de la quimioterapia.

Early Listening Function (ELF): adaptação para a língua portuguesa

OBJETIVO: Traduzir e adaptar culturalmente para a língua portuguesa o questionário Early Listening Function (ELF), e avaliar a confiabilidade do mesmo. MÉTODOS: Foi realizada a tradução do questionário para o idioma Português, revisão das equivalências gramatical e idiomática (traduções reversas) e adaptações linguística e cultural. Além disso, foi avaliada a reprodutibilidade intra-pesquisadores. Após a tradução, o ELF foi aplicado, em ambiente silencioso e ruidoso, em 30 crianças entre zero e três anos de idade, sem histórico de risco para deficiência auditiva, ausência de queixa familiar quanto ao desenvolvimento global da criança e sem indicadores de perda auditiva incapacitante, em diferentes distâncias, em 12 situações de detecção auditiva. RESULTADOS: Os resultados foram analisados com estudo estatístico descritivo a partir da pontuação obtida no ELF. CONCLUSÃO: O instrumento ELF foi traduzido e adaptado culturalmente para a população estudada. No Português, sua denominação manteve a sigla ELF. O estudo permitiu verificar sua confiabilidade para observação e acompanhamento das etapas iniciais do comportamento auditivo.

Improved Communications and Hearing Protection in Helmet Systems: The Communications Earplug

Despite significant advances in hearing protection and compliance with protective standards, military personnel are still subject to noise-induced hearing loss in many combat and combat support operations. Although the Army has experienced a decrease of some 15% in primary hearing loss disability cases since 1986, a fiscal year 2000 report documents a 27.5% increase in audiograms, which demonstrated significant threshold shifts in assessed personnel (N = 841/1,077). Compensation for noise-induced hearing loss disability for the Army alone exceeded $180 million in 1998. Thus, communications and hearing protection remain critical issues for personnel involved in Army operations. Aircraft, ground vehicles, and weapons produce noise levels in excess of the limits defined in current hearing conservation standards. Performance of most helmets, improved over the years, remains marginal with regard to speech intelligibility. Furthermore, these helmets do not provide adequate hearing protection. The communications earplug, which consists of a high-quality earphone coupled with an earplug protector, provides the needed extra protection. It weighs less than 15 g and is comfortable when worn over extended periods. It is considered highly acceptable by seasoned Army aviators and crewmembers.