Niels Christian Stenklev

Presbyacusis—hearing thresholds and the ISO 7029

The purpose of this study was to analyse the changes inpure-tone hearing thresholds with age. We studied a randomsample of 232 elderly subjects with a battery ofaudiological tests, including pure-tone audiometry in theconventional and extended high-frequency range, usingthe normative distributions from the InternationalOrganization for Standardization (ISO) standard 7029for comparison. Sixty otologically normal (ON) subjectswere selected for comparative analysis with theunscreened (US) sample, and for description of genderand age group differences. With the use of a mathematicaltransformation of threshold data, it was found thatthe ISO 7029 normative a coefficient in females may beset too low compared to our sample in the lower frequencies,leading to an underestimation of hearingthresholds in ON females. In our ON sample, hearingthresholds deteriorated with age in the extended highfrequencyaudiometric range. No gender threshold differenceswere found, although the prevalence of unmeasurableresponses was higher in males at some of thesefrequencies. The ON screening criteria in ISO 7029 maybe unreliable in subjects over 60 years of age, as thresholddifferences between ON and US subjects were not consistentat any frequency. Sumario El propósito de este estudio fue analizar los cambios delos umbrales auditivos con tonos puros por efecto de laedad. Estudiamos una muestra de 232 adultos mayorescon una batería de pruebas audiológicas en la que seincluyó la audiometría de tonos puros en los rangos defrecuencias convencional y en el extendido a las frecuenciasagudas, usando como comparación el estandar 7029de las distribuciones normativas de la Organización parala Estandarización Internacional (ISO). Se seleccionaronsesenta sujetos otológicamente normales (ON), parahacer un análisis comparativo con una muestra notamizada (US) y para describir las diferencias por géneroy por grupo de edad. Con el uso de una transformaciónmatemática de los datos de los umbrales, se encontró queel coeficiente normativo a del ISO 7029 en mujeres, puedehaberse fijado demasiado bajo en comparación con nuestramuestra en las frecuencias graves, favoreciendo unasubestimación de los umbrales auditivos en las mujeresON. En nuestra muestra ON, los umbrales auditivos sevieron deteriorados por la edad en el rango audiométricoextendido a las frecuencias agudas. No se encontrarondiferencias en los umbrales por género pero en hombres,la prevalencia de respuestas no medibles en algunas delas frecuencias agudas fue alta. El criterio de identifi-cación en ON con el ISO 7029 puede ser no confiable ensujetos mayores de 60 años mientras que las diferenciasde umbrales entre sujetos ON y US no fueron consistentesen ninguna frecuencia.

The aging ear: An otomicroscopic and tympanometric study

Objective To analyze changes in tympanometric measures with age and to study some otitis-related issues in the elderly (≥ 60 years) population. Material and Methods The study was designed as a combination of a cross-sectional survey and a controlled study. We studied a random sample of 232 elderly subjects using an extended battery of audiological tests, including pure-tone audiometry. tympanometry with a probe frequency of 226 Hz, otomicroscopy and a standardized questionnaire. A sample of 60 otologically normal subjects were selected for comparative analysis with young healthy controls, and for description of age-related changes and gender differences. Results Using linear regression analyses of ear canal volume, middle ear pressure and tympanic membrane compliance on age, no consistently significant change in these parameters with age was found. When these measures were compared between the elderly and the controls, using parametric and non-parametric statistical tests, no significant differences were found for either gender. The only significant gender difference was found for ear canal volume, which was greater for elderly males than for elderly females In the unscreened elderly sample, the adjusted prevalence for reported previous or current otitis media was 15–27% of the population (95% CI). The adjusted prevalence for reported previous or current chronic otitis media (COM) or sequelae thereof was 1–7% (95% CI). With the exception of cerumen obstruction, the prevalence of outer ear canal-related complaints was 1–7% (95% CI). There were some discrepancies between these reported complaints and the findings at otomicroscopy. Although elderly subjects with COM were found to have poorer hearing at speech frequencies than normal elderly subjects. no such effect was found in subjects with scarring or atrophy of the tympanic membrane. The effect of pathological findings at otomicroscopy on tympanometric measures in the elderly sample was highly variable and no consistent association was found. Conclusions No change in middle ear sound transmission, as assessed by tympanometry, occurs with normal aging. Ear canal volume is smaller in elderly females than elderly males, which is potentially relevant to the study of otoacoustic emissions in the elderly. The estimated prevalence of ear canal-related problems, excluding cerumen obstruction, is of such a magnitude that the introduction of partially implanted hearing aids may be warranted in our elderly population.

Damage and functional recovery of the Atlantic cod (Gadus morhua) inner ear hair cells following local injection of gentamicin

This study addresses the ultrastructural and functional damage and subsequent recovery of the inner ear in the Atlantic cod following intrasaccular gentamicin injection. Inner ear damage was assessed using SEM and measurements of AEP following 250-Hz pure-tone stimuli. Data from gentamicin-treated fish were compared with control (no injection) and sham (injection of saline) fish. Control fish had normal response thresholds associated with well-developed hair cell bundles in their macula sacculi. Sham fish had higher response thresholds compared with control fish during the first week post-intervention, but response thresholds were subsequently normal. Treated fish displayed significant inner ear damage associated with an increased average AEP threshold on the third day following treatment. Thereafter, inner ear tissue displayed signs of progressive regeneration until it was comparable to controls from the 14th day. Response thresholds were similar to those of control fish from the 17th day following treatment. These observations suggest that the macula sacculi of Atlantic cod can regenerate towards a near-complete functional and ultrastructural recovery within 17–21 days following ototoxic gentamicin treatment.

Effects of systemic versus local gentamicin on the inner ear in the Atlantic cod, Gadus morhua (L.), relevance for fish hearing investigations.

UNLABELLED Fish models are increasingly being used for hearing research investigations. Aminoglycoside antibiotics that are used for damaging the inner ear hair cells can have systemic side effects leading to death of study animals. This study aimed to compare two methods: (i) systemic (intravenous) and (ii) local (intrasaccular) gentamicin administration for induction of inner ear hair cell damage in the Atlantic cod, Gadus morhua (L.). Hair cell damage was assessed using scanning electron microscopy; hair cell density, prevalence of immature hair cells and kinocilia length were measured. Gentamicin-treated fish were compared with control and sham fish. Intravenous gentamicin led to dose-dependent mortality caused by nephrotoxicity. The only visible effect after treatment was more immature hair cells and shorter kinocilia, the effect on hair cell density was equivocal. Following intrasaccular gentamicin treatment, fish mortality was negligible, and hair cells were damaged regardless of dose. Here, we observed decreased hair cell density, high prevalence of immature hair cells, and significantly shortened kinocilia. CONCLUSION intrasaccular injection is preferable to intravenous injection of gentamicin for the study of ototoxicity in the Atlantic cod.

Transient evoked otoacoustic emissions in the elderly.

The purpose of this study was to analyse the changes in transient evoked otoacoustic emissions (TEOAEs) with age. We studied 232 subjects above 60 years of age with a battery of audio-logical tests, including TEOAEs. Our criterion for the presence of TEOAEs was based on a cutoff at overall wave reproducibility 55% or overall response level 4 dB SPL. The prevalence of TEOAEs in left ears was 55.6%. No TEOAEs were found in subjects with a pure-lone average (PTA) above 40 dB HL. In the subgroup with TEOAEs, a significant decrease in overall wave reproducibility with age was found. We compared 45 normal-hearing elderly subjects with TEOAEs with a control group of 20 normal-hearing young adults. The elderly had significantly lower mean overall response levels and mean overall wave reproducibility. Average hearing level was significantly higher in the elderly than in controls. We conclude that the prevalence of TEOAEs decreases with age, and that the overall response level and overall reproducibility decrease with age. This decrease may not be seen in isolation from the increase in hearing threshold level. El propósito de cste estudio fue analizar los cambios en las emisiones otoacústicas evocadas por transitorios (TEOAEs) con la edad. Estudiamos 232 sujetos con edades por encima de los 60 años, con una batería de prueba audiológicas que incluían las TEOAEs. Nuestro critcrio para la presencia de las TEOAEs se basó en un corte al 55% de reproducibilidad global de la onda, o a un nivel de respuesta global de 4 dB SPL. La prevalencia de las emisiones (TEOAEs) en oídos izquierdos fue de 55.6%. No se encontraron emisiones en sujetos con promedios tonales (PTA) por encima de 40dB HL. En el sub-grupo con TEOAEs, se encontró una disminución significativa en la reproductibilidad global de la onda relacionada con la edad. Comparamos 45 ancianos con audición normal y con TEOAEs, con un grupo control de 20 adullos jóvenes normooyentes. Los ancianos mostraron niveles globales de respuesta promedio y promedios de reproducibilidad global de la onda significativamente menores. El nivel auditivo promedio fue significativamente mayor en los ancianos que en los controles. Concluimos que la prevalencia de las TEOAEs disminuye con la edad y que el nivel global de respuesta y la reproducibilidad global disminuyen también con la edad. Esta disminución de debe observarse aisladamente en relación con el deterioro en los umbrales de audición.

Hearing loss and tinnitus in rock musicians: A Norwegian survey.

Our focus in this study was to assess hearing thresholds and the prevalence and characteristics of tinnitus in a large group of rock musicians based in Norway. A further objective was to assess related factors such as exposure, instrument category, and the preventive effect of hearing protection. The study was a cross-sectional survey of rock musicians selected at random from a defined cohort of musicians. A random control group was included for comparison. We recruited 111 active musicians from the Oslo region, and a control group of 40 nonmusicians from the student population at the University of TromsØ. The subjects were investigated using clinical examination, pure tone audiometry, tympanometry, and a questionnaire. We observed a hearing loss in 37.8% of the rock musicians. Significantly poorer hearing thresholds were seen at most pure-tone frequencies in musicians than controls, with the most pronounced threshold shift at 6 kHz. The use of hearing protection, in particular custom-fitted earplugs, has a preventive effect but a minority of rock musicians apply them consistently. The degree of musical performance exposure was inversely related to the degree of hearing loss in our sample. Bass and guitar players had higher hearing thresholds than vocalists. We observed a 20% prevalence of chronic tinnitus but none of the affected musicians had severe tinnitus symptomatology. There was no statistical association between permanent tinnitus and hearing loss in our sample. We observed an increased prevalence of hearing loss and tinnitus in our sample of Norwegian rock musicians but the causal relationship between musical exposure and hearing loss or tinnitus is ambiguous. We recommend the use of hearing protection in rock musicians.

Hearing loss before and after cisplatin-based chemotherapy in testicular cancer survivors: a longitudinal study

Abstract Background: Hearing loss is a well-known long-term effect after cisplatin-based chemotherapy (CBCT) in testicular cancer survivors (TCS), but longitudinal data are sparse. We evaluate hearing loss and the impact of age in TCS treated with CBCT in this longitudinal study. Material and methods: Forty-six TCS treated with CBCT 1980–1994 with audiograms (0.25–8 kHz) pre-chemotherapy (PRE) and at a follow-up survey (SURV) after median 10 years were included (cases). Audiograms at SURV from 46 age-matched TCS without CBCT were included as controls. Linear regression was performed to evaluate predictors for change in the hearing threshold level (HTL) from PRE to SURV. Two definitions of a audiogram-defined hearing loss was applied if: (1) mean HTL for both ears exceeded 20 dB at any frequency 0.25–8 kHz (American Speech-Language-Hearing Association (ASHA) definition) and (2) average HTL for the frequencies 0.5, 1, 2 and 4 kHz exceeded 20 dB (WHO-M4 definition). Self-reported hearing impairment (SURV) was assessed by a questionnaire. Results: Age and cisplatin dose was significantly associated with a greater change in HTL for the frequencies 2–8 kHz. For the 8 kHz frequency, each 100 mg increase in cumulative cisplatin dose was associated with a deterioration of 3.6 dB (95% CI 1.8–5.3, p < .001). The prevalence of hearing loss (ASHA) among cases was 33% PRE, 70% at SURV and 65% among controls at SURV (cases vs. controls, p = .66). According to M4, the prevalence of hearing loss among cases was 6.5% PRE, 13% at SURV and 2.2% among controls at SURV (cases vs. controls, p = .049). Twenty-nine percent of cases, and 33% of controls (p = .70) reported hearing impairment at SURV. Conclusion: Cisplatin is associated with a hearing loss particularly at higher frequencies. Age appear to be an important factor for hearing loss regardless of treatment. The ASHA definition overestimates the hearing problem.

Transient evoked otoacoustic emissions in rock musicians

Abstract Objective: Our focus in this study was the assessment of transient evoked otoacoustic emissions (TEOAEs) in a large group of rock musicians. A further objective was to analyse tinnitus among rock musicians as related to TEOAEs. Design: The study was a cross-sectional survey of rock musicians selected at random. A control group was included at random for comparison. Study sample: We recruited 111 musicians and a control group of 40 non-musicians. Testing was conducted by using clinical examination, pure tone audiometry, TEOAEs and a questionnaire. Results: TEOAE SNR in the half-octave frequency band centred on 4 kHz was significantly lower bilaterally in musicians than controls. This effect was strongly predicted by age and pure-tone hearing threshold levels in the 3–6 kHz range. Bilateral hearing thresholds were significantly higher at 6 kHz in musicians. Twenty percent of the musicians had permanent tinnitus. There was no association between the TEOAE parameters and permanent tinnitus. Conclusions: Our results suggest an incipient hearing loss at 6 kHz in rock musicians. Loss of TEOAE SNR in the 4 kHz half-octave frequency band was observed, but it was related to higher mean 3–6 kHz hearing thresholds and age. A large proportion of rock musicians have permanent tinnitus.

Hearing in the elderly: a test protocol and preliminary results

Hearing deteriorates with age. ISO 7029 (2000) presents data on hearing threshold as a function of sex and age up to 70 years. There is a need for an extension of these data beyond 70 years. There is also a need for testing the central component of hearing in the elderly. A test protocol was established, and groups of subjects aged 60 to ≥ 90 were selected. After a questionnaire and an ear examination, the following tests were performed: air-conduction pure-tone audiometry in the frequency range of 125-16 kHz, tympanometry, speech recognition score in quiet conditions, transient evoked otoacoustic emissions (TEOAE) and cognitive cortical evoked potentials (MMN, P300, N400). Preliminary tests showed the expected age-related reduced hearing sensitivity as seen from the pure-tone audiograms, a lower speech recognition score in the oldest subjects, lack of TEOAE and poor cognitive responses in the elderly. Statistical data will be developed based on the complete material of around 400 subjects.

Tinnitus, Anxiety, Depression and Substance Abuse in Rock Musicians a Norwegian Survey

OBJECTIVE Rock musicians are known to have an increased prevalence of hearing loss and tinnitus. The aims of the present study were to examine the distribution of anxiety and depression symptoms among rock musicians with or without tinnitus and how these mental health indicators and internal locus of control influenced upon their tinnitus symptom concerns and the degree to which the tinnitus affected their lives. DESIGN The study was a questionnairebased cross-sectional survey of subjects selected from a cohort of rock musicians. We recruited 111 active musicians from the Oslo region, and a control group of 40 non-musicians from the student population at the University of Tromso. RESULTS Among the rock musicians 19.8% reported permanent tinnitus vs. 0% among the controls. Musicians more often reported anxiety symptoms than controls (35.1% vs. 17.5%), however this prevalence was not different in musicians with and without tinnitus. Tinnitus-affected musicians reported depressive symptoms, significantly more than controls (13.6% vs. 5%). Rock musicians consumed more alcohol than controls, but alcohol consumption was unrelated to severity of tinnitus. Drug abuse was not more prevalent in rock musicians than in controls. Duration of tinnitus, internal locus of control, sleep disturbance and anxiety were significant predictors of how affected and how concerned musicians were about their tinnitus. CONCLUSION Rock musicians are at risk for the development of chronic tinnitus, and they have an increased prevalence of anxiety. There is an association between chronic tinnitus and depressive symptoms in rock musicians, but our results are ambiguous. Although rock musicians have a chronic exposure to noise, noise-induced hearing loss is not the sole causative agent for the development of tinnitus.