Influencia de las zonas cocleares muertas sobre la autopercepción de las habilidades auditivas en adultos con hipoacusia sensorioneural bilateral / Influence of cochlear dead regions on self-perception hearing abilities in adults with bilateral sensorineural hearing loss

RESUMEN Introducción: Las zonas cocleares muertas son áreas de la membrana basilar donde las células ciliadas y/o fibras del nervio auditivo no son funcionales, lo que puede alterar el análisis temporal de una señal acústica. Los efectos funcionales que podrían generar aún no son claros, y establecerlos a través del uso de cuestionarios de autopercepción, proporcionaría información de utilidad para el manejo audiológico de los pacientes. Objetivo: Determinar la relación entre la presencia de zonas cocleares muertas y la autopercepción de las habilidades auditivas en adultos con hipoacusia sensorioneural bilateral. Material y método: Se evaluaron 20 sujetos con hipoacusia bilateral simétrica, entre 51 y 75 años, sin antecedentes de uso de audífonos. Las zonas cocleares muertas fueron evaluadas mediante la prueba TEN en 1, 2, 3 y 4 kHz; y la autopercepción de habilidades auditivas fue medida en los participantes a través del cuestionario de doce preguntas, IROS12. Resultados: La presencia de zonas cocleares muertas se observó en 10 pacientes. No existiendo una diferencia significativa entre grupos, sin embargo, se observaron puntuaciones más bajas de IROS12 en sujetos con zonas cocleares muertas. Conclusiones: La percepción de dificultades auditivas de individuos que presentan una hipoacusia sensorioneural bilateral simétrica moderada, con presencia de zonas cocleares muertas, no difiere significativamente de aquellos individuos que no presentan zonas cocleares muertas.

ABSTRACT Introduction: Cochlear dead regions are areas of the basilar membrane where the hair cells and/or auditory nerve fibers are not functional, which can alter the temporal analysis of an acoustic signal. The functional effects that could generate still are not entirely clear, and set through the use of self-perception questionnaires, provide useful information for audiological management of patients. Aim: To investigate the relationship between the presence of cochlear dead regions and the self-reported of listening difficulties of adults with bilateral sensorineural hearing loss. Material and Method: Twenty adults with symmetric bilateral sensorineural hearing loss, aged 51 to 75 years were tested, without previous story of use of hearing aids. Cochlear dead regions were tested using the TEN test at 1, 2, 3 and 4 kHz. The questionnaire of twelve questions, IROS12, was applied to the participants. Results: Cochlear dead regions were present in 10 participants. No significant differences were observed between groups, however lower IROS12 scores were observed in those who had present of dead regions. Conclusion: The perception of hearing difficulties in individuals with bilateral sensorineural hearing loss with cochlear dead regions did not differ significantly from those individuals without cochlear dead regions.

The Effects of Cochlear Dead Regions on Speech Recognition Ability in Patients with Sensorineural Hearing Loss / 听力学及言语疾病杂志

Objective To study the distribution of cochlear dead regions in the cochlea with sensorineural hearing loss (SNHL),and to investigate the effects of cochlear dead regions on speech recognition.Methods A total of 41 SNHL patients (81 ears) were divided into the cochlear dead region group (35 ears) and the group without cochlear dead regions (46 ears) by using threshold equalizing noise test (TEN test).Then we used speech recognition threshold (SRT) and speech discrimination score (SDS) tests to study the distribution of cochlear dead regions and to investigate the effects of cochlear dead regions on speech recognition.Results There were 41 cases (81 ears) sensorineural hearing loss patients and 43.21％ (35/81) were found to have the cochlear dead regions.The cochlear dead region detection rate for patients with mild SNHL was 0(0/11);in patients with moderate SNHL,the cochlear dead region detection rate was 24.1％ (7/29);in patients with severe SNHL the cochlear dead region detection rate was 66.7％ (24/36);the cochlear dead regions of profound SNHL patients were 80.0％ (4/5) respestively.The existence of the cochlear dead regions was significantly correlated with the degree of hearing loss (P＜0.05).The proportion of high frequency cochlear dead regions (16 ears)was much higher than that of the low frequency cochlear dead regions(8 ears).There was no significant reduction of SRT and SDS between high and low cochlear dead regions groups(P＞0.05).The SRT and SDS of the patients with cochlear dead regions were 61.63± 16.76 dB,86.35％±12.03％.The SRT and SDS of the patient with no cochlear dead regions were 75.54 ± 9.56 dB and 64.97％±20.84％.Theresults showed a significant (P＜0.05) reduction of SRT and SDS between the patient with cochlear dead regions and the patient with no cochlear dead regions.Conclusion The greater the degree of hearing loss is,the higher possibility of the existence of cochlear dead regions there is.Cochlear dead regions are common in high frequencies than in low frequencies.The speech recognition ability can be affected.

Clinical Application of the Threshold Equalizing Noise Test in Patients with Hearing Loss of Various Etiologies: A Preliminary Study

BACKGROUND AND OBJECTIVES: We aimed to make a preliminary assessment of the prevalence of cochlear dead regions (DRs) and the factors affecting the results of the threshold-equalizing noise (TEN) test in patients with hearing loss of various etiologies. SUBJECTS AND METHODS: Between May and July 2014, 109 patients (191 ears) with hearing loss who visited our outpatient clinic were prospectively enrolled. Pure tone audiometry and TEN (HL) test were performed for all the patients. DR at each frequency was indicated by masked thresholds of > or =10 dB above the TEN level and > or =10 dB above the absolute threshold. RESULTS: DR was present in 15.7% (n=30) of the 191 ears. According to disease entity, 16.6% of patients with sensorineural hearing loss had a DR. However, DR was absent in patients with chronic otitis media. According to audiometric configurations, DR was most common in moderately severe, flat hearing loss. Significantly worse hearing thresholds for both mean hearing level and hearing threshold at each frequency were found in the presence of DR (p<0.001). Logistic regression analysis showed that only the mean hearing level (odds ratio: 1.053, 95% confidence interval: 1.021-1.085) affected the presence of DR. CONCLUSIONS: Although performance of the TEN test is limited by frequencies and hearing levels, it provides additional information regarding DRs and may therefore have the potential to be used as a prognostic tool for diverse diseases causing hearing loss.

O diagnóstico das zonas mortas na cóclea e sua importância no processo de reabilitação auditiva / Diagnosing cochlear \"dead\" regions and its importance in the auditory rehabilitation process

Cada vez mais na prática da audiologia é indispensável um bom diagnóstico audiológico, para que se tenha conhecimento das necessidades do paciente para seleção e adaptação de próteses auditivas. OBJETIVO: Expor literaturas recentes que referem conceitos de zonas mortas na cóclea, estratégias de diagnóstico e a importância deste no processo de seleção e adaptação de próteses auditivas. METODOLOGIA: Realizou-se um levantamento bibliográfico sobre zonas mortas na cóclea. As zonas mortas na cóclea foram descritas como regiões onde as células ciliadas internas e/ou neurônios adjacentes não se encontram funcionais. Assim, nessas regiões a informação gerada pela vibração da membrana basilar não é transmitida ao sistema nervoso central. Porém, um tom com freqüência correspondente a zona morta, desde que suficientemente intenso, pode ser percebido em regiões próximas a esta zona, onde às células ciliadas internas e/ou fibras nervosas ainda apresentam-se funcionais. CONCLUSÃO: A identificação das zonas mortas na cóclea está sendo utilizada visando melhores resultados no processo de seleção e adaptação de próteses auditivas, pois as informações geradas pelas CCI ao nervo auditivo são importantes para um melhor reconhecimento dos sons, principalmente os sons da fala.

A good audiologic diagnosis is increasingly more important in the practice of audiology, in order to understand patients needs for selection and fitting of hearing aid devices. AIM: Show recent literature that mention the concept of cochlear dead regions, diagnostic strategies and its relevance in the process of selection and fitting of hearing aids. METHODS: to carry out a bibliographical survey on dead cochlear regions. Dead cochlear regions were described as regions where inner hair cells and/or adjacent neurons do not work. Therefore, in these regions, the information generated by basilar membrane vibration is not transmitted to the central nervous system. However, a tone at a frequency correspondent to that of dead regions, provided it being sufficiently intense, can be perceived in regions near this zone where inner hair cells and/or nervous fibers still work. CONCLUSION: The identification of dead regions in the cochlea is used to obtain better results in the process of selection and fitting of hearing aids because the pieces of information generated by inner hair cells to the auditory nerve are important to better identify sounds, mainly those related to speech.