Prevalence of noise-induced hearing loss in student musicians

Abstract

This study describes the prevalence and characteristics of noise-induced hearing loss (NIHL) in student musicians (N = 329) aged 18–25 years. Students completed a questionnaire regarding exposures before a hearing assessment. NIHL was defined by the presence of a notch 15 dB in depth at 4000 or 6000 Hz relative to the best preceding threshold. Overall prevalence of NIHL was 45%, with 78% of notches occurring at 6000 Hz. The proportion of the total population with bilateral notching at any frequency was 11.5%, mostly occurring at 6000 Hz. There was a significant increase in the frequency of notching in students who reported more than two hours per day of personal practice. There were no significant associations for instrument group or other noise exposures. The data suggest that susceptibility to NIHL among students of music is not uniform and cannot be ascribed solely to the instrument played and other exposures. Students with bilateral losses tend to have deeper notches and may represent a group that has an inherent predisposition to NIHL.

Sumario

Este estudio describe la prevalencia y las características de la hipoacusia inducida por ruido (NIHL) en estudiantes de música (N = 329) con edades entre 18 y 25 años. Los estudiantes completaron un cuestionario sobre exposición a ruido antes de la evaluación auditiva. Se definió NIHL como la presencia de una muesca de 15dB en 4000 o 6000Hz con relación al mejor umbral precedente. La prevalencia general de NIHL fue de 44%, con 78% de las muescas en 6,000 Hz. La proporción de la población total con muescas bilaterales en cualquier frecuencia fue de 11.5%, en su mayoría a 6,000 Hz. Hubo un incremento significativo en la frecuencia de la muescas en los estudiantes que reportaban más de dos horas al día de práctica profesional. No hubo una asociación significativa con grupos de instrumentos u otra exposición a ruido. Los datos sugieren que la susceptibilidad a NIHL entre los estudiantes de música no es uniforme y no puede atribuirse solamente al instrumento tocado o a otras exposiciones. Los estudiantes con pérdida bilateral tienden a tener muescas más profundas y pueden representar un grupo que tenga una predisposición inherente a la NIHL.     

Protective effect of a purified polyphenolic extract from Ecklonia cava against noise-induced hearing loss: Prevention of temporary threshold shift

ObjectiveNoise is one of the most common causes of hearing loss. Approximately 16% of American teenagers (12–19 years) have hearing loss caused by loud noise. The implication of noise-induced hearing loss (NIHL) in teenagers has received increasing attention. Although temporary threshold shift (TTS), a type of NIHL, is a transient hearing loss, it can accelerate age-related hearing loss. Reactive oxygen species are a primary cause of TTS. As the polyphenols from Ecklonia cava are known to have potent antioxidant effects, we investigated the protective effects of a purified polyphenolic extract of Ecklonia cava (PPEE) against TTS in mice.MethodsThe radical-scavenging activity of PPEE was evaluated using the 1,1-diphenyl-2-picrylhydrazyl assay. The PPEE + Noise and Saline + Noise groups were administered intraperitoneal PPEE (100 mg/kg) and saline, respectively, for 5 days before exposure to noise at 100 dB SPL for 60 min. Hearing ability was assessed following noise exposure using auditory brainstem responses and distortion product otoacoustic emissions.ResultsPPEE exhibited significant radical scavenging activity. The ABR threshold shifts 1 day after exposure to noise at 16 kHz and 1, 7, and 14 days after exposure to noise at 32 kHz, were significantly less in the PPEE + Noise than in the Saline + Noise group. One day after noise exposure, mice in the PPEE + Noise group showed a significant degree of protection in relation to their DPOAE level at f2, 17, and 28 kHz.ConclusionsThese findings suggest that PPEE may be a potential preventive agent against TTS. In addition, as a food ingredient approved by the United States Food and Drug Administration, PPEE may be administered to those who are exposed to noise inevitably with little likelihood of adverse effects, thereby contributing to the prevention of TTS.     

Iris pigmentation and susceptibility to noise-induced hearing loss

The purpose of this retrospective study is to examine the possible association between iris pigmentation and susceptibility to noise-induced hearing loss in 2407 noise-exposed workers. The workers were between 16 to 65 years of age and were exposed to 2 to 42 years of work-related noise. Results demonstrated that dark-eyed workers presented a greater percentage of normal pure-tone thresholds than fair-eyed workers. Fair-eyed workers had threshold averages of 25.1 dB (right ear) and 26.0 dB (left ear) at 3, 4, and 6 kHz, which were significantly worse than workers with dark irises, with threshold averages of 15.8 dB and 17.2 dB in the right and left ear, respectively (p<0.01). Fair-eyed workers with less than 10 years of noise exposure had the same audiometric pattern as the dark-eyed workers exposed for more than 10 years. Workers not exposed to noise did not present significant differences in their audiometric pattern as a function of eye colour. These results suggest that iris pigmentation may be an additional indication of susceptibility to noise-induced hearing loss.     

氧化应激与噪音性聋发病机制及治疗进展

噪音性聋属常见职业病,其致病机制的研究涉及组织、分子及基因等方面,衍生出机械学说、代谢学说、血管学说、钙离子平衡失调、神经因子缺乏及钾离子循环途径等学说。就氧化应激机制在噪音性聋发病中的作用及治疗进行综述。     

Sound conditioning reduces noise-induced permanent threshold shift in mice

The phenomenon of conditioning-related protection, whereby prior exposure to moderate-level, non-traumatic, sound protects the ear from subsequent traumatic exposure, has been documented in a number of mammalian species. To probe the molecular mechanisms underlying this effect, the mouse would be a useful model; however, a previous study reported no conditioning effects in this species (Fowler et al. , 1995). In our study, mice (CBA/CaJ) were exposed to a traumatic octave-band noise (8-16 kHz at 100 dB SPL for 2 h) with, or without, prior exposure to a sound-conditioning protocol consisting of exposure to the same noise band at lower sound pressure levels. Two conditioning protocols were investigated: one (81 dB SPL for 1 week) was analogous to those used in other conditioning studies in mammals; the second was significantly shorter (89 dB SPL for 15 min). Noise-induced permanent threshold shift (PTS) was assessed in a terminal experiment, after the traumatic exposure, via compound action potentials. Neither conditioning protocol elevated threshold, indeed both protocols increased amplitudes of distortion product otoacoustic emissions when animals were conditioned but not traumatized. Both conditioning exposures significantly reduced PTS from the subsequent traumatic exposure, compared to groups exposed without prior conditioning. Protective effects of 15-min conditioning were maximal when the condition-trauma interval was 24 h; protection disappeared when the traumatic exposure was presented 48 h after conditioning. These data are consistent with the view that protein synthesis is required for expression of the protective effect. The enhancement of distortion products in the condition-only state suggests that conditioning changes outer hair cell function.     

褪黑素对噪声性聋的防护作用

目的通过检测耳蜗中活性氧(reactive oxygen species,ROS)的含量研究褪黑素(melatonin,MLT)对噪声性聋的防护作用.方法雄性杂色豚鼠40只,随机分为4组,每组10只.第1组为正常对照组,不接触噪声,仅肌肉注射褪黑素,注射褪黑素的时间及剂量与第2组相同.第2、3、4组每天接触倍频程连续噪声(中心频率为4kHz,强度为100dB SPL)8小时,连续3天.第2组于噪声暴露前24h、即刻及噪声暴露中肌肉注射褪黑素3天.第3组在相同时间肌肉注射与第2组相同剂量的生理盐水.第4组为单纯接触噪声对照组.所有动物均于噪声暴露前及暴露后立即检测听性脑干反应(ABR)阈值,噪声暴露3天测完ABR阈值后,立即断头处死豚鼠,取出双侧耳蜗,并测定其活性氧含量.结果噪声暴露后,第2组的ABR阈移及活性氧含量分别与第3、4组比较,差异均有显著性.结论褪黑素能够减少噪声暴露后耳蜗中增多的活性氧水平,可能对噪声性耳蜗损伤具有一定的防护作用.     

谷氨酰胺合成酶对噪声引起的听力损失的保护作用

目的观察外源性谷氨酰胺合成酶对噪声暴露引起豚鼠听力损失的保护作用。方法应用豚鼠全耳蜗灌流技术，右耳耳蜗灌流人工外淋巴液和不同浓度的谷氨酰胺合成酶2小时，同时持续性给予右耳白噪声2小时，分别记录噪声暴露前和噪声暴露后的耳蜗微音电位（CM）；并且应用透射电镜技术观察噪声暴露前后耳蜗形态学的变化。结果全耳蜗灌流人工外淋巴液同时给予100dB SPL的白噪声2小时，CM幅度显著下降，并且其非线性特点消失，复合动作电位（CAP）阈值为79．5dB SPL；全耳蜗灌流0．5μ／L和1μ／L的谷氨酰胺合成酶同时给予100dB SPL的白噪声2小时，CM幅度下降减轻，但CM的非线性特点仍不存在，CAP阈值升高，其中灌流1μ／L的谷氨酰胺合成酶时CM幅度和CAP阈值的恢复更明显。形态学显示1μ／L谷氨酰胺合成酶＋噪声组内毛细胞及其下方传入神经纤维基本正常，但是外毛细胞仍存在空化。结论谷氨酰胺合成酶通过摄取噪声暴露时过度释放的谷氨酸，对噪声性听力损失有部分保护作用。     

Mechanisms of noise-induced hearing loss potentiation by hypoxia

Potentiation of noise-induced permanent threshold shift (PTS) by hypoxia has been reported [Hear. Res. 172 (1–2) (2002) 186]. In this study in rats, effects of noise (110 dB SPL), hypoxia (10% O₂), and their combination have been determined on different cochlear potentials and on the expression of genes coding proteins in the outer hair cell (OHC) membrane skeleton (β-actin) and in the mitochondrial respiratory chain (SDHa & b). The noise exposure alone caused CAP threshold shift only in the noise-band. The combined exposure to noise and hypoxia caused an about 40-dB PTS at all frequencies within and above the noise band. Loss of the cochlear amplification was not always related to the CM-suppression. SP was only affected at high frequencies by the combined exposure. Gene expression of β-actin was up-regulated by the noise exposure, which was blocked by hypoxia. Gene expression of SDHa was also up-regulated by the noise and the combined exposure. The data suggest that loss of the cochlear active process, due to damage to the OHC membrane skeleton and to the cellular energy generation system, is related to the noise-induced hearing loss potentiation by hypoxia. Inner hair cell damage may also be involved in the hypoxia potentiation in the basal turn.     

饱和氢生理盐水对噪声性聋的预防作用

目的探讨饱和氢生理盐水是否具有预防噪声性聋的作用。方法取清洁级白色健康、ABR阈值正常豚鼠15只,雌雄不限,体重250～300g。随机分成3组,空白对照组5只;生理盐水对照组5只;饱和氢生理盐水处理组5只,于噪声暴露前1小时给予腹腔注射饱和氢生理盐水,1ml/100g。给予脉冲噪声(压力峰值157dBSPL,脉宽0.25ms)连续暴露100次。于脉冲噪声暴露后即刻、第1天、第2天、第4天、第8天测听性脑干反应(auditory brainstem respons,ABR);第8天采用琥珀酸脱氢酶(Succinate Dehydrogenase,SDH)染色观察外毛细胞的形态学变化。结果噪声暴露后,饱和氢生理盐水处理组在各时间点的ABR阈值均明显低于对照组,有统计学意义(P<0.01);光学显微镜下可见空白对照组及生理盐水对照组动物耳蜗SDH几乎不着色,细胞肿胀或缺失,排列不规则;饱和氢生理盐水处理组SDH着色较深,存在散在片状无染色区,细胞缺失明显减少,排列较规则;耳蜗底回同一部位外毛细胞存活计数,空白对照组为45.17±12.15个,盐水对照组为44.50±10.02个,二者无明显差别;饱和氢生理盐水处理组分别为116.50±2.38个与对照组有统计学意义(P<0.05)。结论腹腔注射饱和氢生理盐水可拮抗强脉冲噪声引起的耳蜗损伤,能够对噪声性聋起到一定程度的预防作用。     

Follow-up of auditory-evoked potentials and temporary threshold shift in subjects developing noise-induced permanent hearing loss

The effects of auditory fatigue, using a temporary threshold shift (TTS) paradigm, on cochlear microphonics (CM) and on auditory brainstem-evoked potentials (ABEP), were studied in normal-hearing subjects during the development of permanent threshold shift (PTS). Behavioral threshold shifts were accompanied by different effects on CM and on ABEP, as PTS was gradually induced by occupational noise. Measures of the effect of increasing stimulus rate (ISR) on ABEP revealed decreased latency shifts during auditory fatigue. ABEP proved useful in early detection of changes in the auditory system, resulting from exposure to noise. In addition, this study further supports the suggestion that TTS acts as a peripheral attenuator of the effect of ISR on the central auditory pathway.     

Assessment of outer hair cell function and blood antioxidant status of rabbits exposed to noise and metal welding fumes

OBJECTIVES: To investigate the interaction between welding fumes and noise in causation of hearing impairment. METHODS: Groups of rabbits (n=6) were exposed to noise, welding fumes or combination of both prior to Distortion Product Otoacoustic-Emissions (DPOAEs) analysis. The function of outer hair cells (OHCs) was examined by DPOAE assessment over a broad range of frequencies. Variations in DPOAE amplitude were compared between control (n=6) and exposed (n=18) groups. RESULTS: The DPOAEs levels measured at different frequencies (1379-6299 Hz) were found to decrease significantly (P<0.05) in rabbits exposed to 110 dB sound pressure level (SPL) broadband noise (8h/day, 12 days). In rabbits, exposed to carbon-steel welding fumes alone (157 mg/m(3)), the threshold shift was limited to the high frequencies (2759-6299 Hz), whereas, mixed exposure to noise and fumes resulted in reduction of DPOAEs at all the frequencies. Changes in DPOAEs were associated with increased susceptibility of erythrocytes to oxidation (P<0.05). Exposure to noise or fumes alone or simultaneously, suppressed total antioxidant ability of plasma as measured by ferric reducing ability of plasma (FRAP). Noise alone or in combination with fumes resulted in depletion of blood glutathione (GSH). Despite suppression of FRAP in the exposed groups, GSH was found to remain unchanged due to welding fumes suggesting that antioxidants other than GSH are affected by toxicants present in metal welding fumes. CONCLUSION: Exposure to very high levels of welding fumes can increase noise-related effects on OHC function by extending hearing threshold shift to wide band frequencies.     

天麻素对噪声性耳蜗损伤防护作用的实验研究

目的观察天麻提取液-天麻素对噪声性耳蜗损伤的防护作用.方法豚鼠28只随机分成3组,正常组8只、噪声组10只和天麻素组10只,暴露于噪声的同时加用天麻素.所有豚鼠均作ABR、耳蜗基底膜铺片和扫描电镜观察.结果噪声组(64.37dB)和天麻素组(31.25dB)ABR阈值均显著高于正常组(20dB),但天麻素组显著低于噪声组(P＜0.01).天麻素组耳蜗毛细胞和静纤毛损害均轻于噪声组.结论天麻素能降低豚鼠噪声暴露后的ABR阈值,减轻毛细胞损害,对噪声性耳蜗损伤有防护作用.     

Differences between acoustic trauma and other types of acute noise-induced hearing loss in terms of treatment and hearing prognosis

Abstract

Objectives: To evaluate the differences between acoustic trauma (AT) and other types of acute noise-induced hearing loss (ANIHL), we performed a literature search and case reviews.

Methods: The literature search based on online databases was completed in September 2016. Articles on ANIHL and steroid treatment for human subjects were reviewed. The source sounds and treatment sequelae of our accumulated cases were also reviewed. Hearing loss caused by gun-shots and explosions was categorized into the AT group, while hearing loss caused by concerts and other noises was categorized into the ANIHL group.

Results: Systemic steroid treatment did not appear to be effective, at least in the AT group, based on both the literature and our case reviews. However, effective recovery after treatment including steroids was observed in the ANIHL group. The difference in hearing recovery between the AT and ANIHL groups was statistically significant (p?=?.030), although differences in age, days from the onset to treatment and pretreatment hearing levels were not significant.

Conclusions: Hearing recovery from AT is very poor, whereas, ANIHL is recoverable to some extent. Therefore, it is essential to differentiate between these two groups for accurate prediction of the hearing prognosis and evaluation of treatment effects.     

微量元素硒对噪声性聋防护作用的实验研究

目的探讨微量元素硒（Se）对豚鼠噪声性听力损伤的保护作用。方法雄性杂色豚鼠40只,体重250～350g,随机分为正常对照组、Se组、Nacl＋噪声组和Se＋噪声组,每组10只。正常对照组不作任何处理,Se组仅连续5d腹腔注射亚硒酸钠（Na2SeO30.7mg/kg,1次/d）,Nacl＋噪声组在噪声暴露前连续5d腹腔注射等量生理盐水（0.9%Nacl）,Se＋噪声组在噪声暴露前连续5d腹腔注射Na2SeO3,均为每日1次。采用窄带噪声,中心频率4kHz,强度为120dBSPL,持续4h。所有动物均于噪声暴露前行脑干诱发电位检测（ABR）;噪声暴露后每组各取5只立即断头处死,取出双侧耳蜗测谷胱甘肽过氧化物酶（GSH-Px）活性,各组剩余的5只于1、10d后测ABR,最后一次测完ABR后处死,取基底膜铺片染色。结果 Nacl＋噪声组和Se＋噪声组于1、10d后的ABR阈值较噪声暴露前有明显提高,差异有统计学意义;Nacl＋噪声组在噪声暴露前后的阈移较Se＋噪声组高,差异有统计学意义。Se组的GSH-Px活性比正常对照组及Se＋噪声组比Nacl＋噪声组高,差异有统计学意义。耳蜗基底膜铺片可见Nacl＋噪声组和Se＋噪声组中的凋亡、坏死和缺失的细胞,Nacl＋噪声组的受损率高于Se＋噪声组,具有统计学差异。结论硒能增加耳蜗组织中GSH-Px的活性,而GSH-Px作为一种抗氧化酶可能中和一部分因噪声刺激而产生的氧自由基/活性氧,对噪声性耳蜗损伤具有一定的防护作用。     

Speech-in-noise screening tests by internet,Part 2: Improving test sensitivity for noise-induced hearing loss

Abstract

Objective: An easily accessible screening test can be valuable in the prevention of noise-induced hearing loss (NIHL). The Dutch National Hearing Foundation developed ‘Earcheck’, an internet-based speech-in-noise test, presenting CVC-words in stationary broadband noise. However, its sensitivity to detect NIHL appeared to be low, 51% (, part 1). The aim of the current study is to examine ways to improve Earcheck's sensitivity for (early) NIHL using different forms of noise filtering. Design: The test's stationary broadband masking noise is replaced by six alternatives, including noises that have been temporally modulated, spectrally filtered by high-pass or low-pass filters, and combinations of temporal modulation and spectral filtering. Study sample: In this multi-centre study, 49 normal-hearing and 49 subjects with different degrees of NIHL participated. Results: Hearing-impaired subjects deviated more clearly from normal performance when executing the test with alternative masking noises, except for the high-pass filtered conditions. Earcheck with low-pass filtered noise made the best distinction between normal hearing and NIHL, without reducing test reliability. The use of this noise condition improved the sensitivity of Earcheck to 95%. Conclusion: The use of low-pass filtered masking noise makes speech-in-noise tests more sensitive to detect NIHL in an early stage.

Sumario

Objetivo: Una prueba de tamiz accessible podría tener valor en la prevención de hipoacusia inducida por ruido (NIHL). La Fundación Nacional Holandesa para la Audición desarrolló la prueba “Earcheck”; una prueba de lenguaje en ruido por internet que presenta palabras CVC en ruido de banda ancha estacionario. Sin embargo, al parecer su sensibilidad para detectar la hipoacusia inducida por ruido es baja, 51% (Leensen et al, parte 1, 2011). El objetivo de este estudio es examinar las formas para mejorar la sensibilidad de Earcheck en la detección de NIHL (incipiente), utilizando diferentes formas de filtración del ruido. Diseño: el ruido estacionario enmascarante de banda ancha de la prueba, es sustituído por seis diferentes alternativas, incluyendo ruidos que han sido temporalmente modulados, espectralmente filtrados por filtros pasa bajo o pasa alto y combinaciones de modulación temporal y filtración espectral. Muestra: en este estudio multicéntrico participaron 49 normoyentes y 49 sujetos con diferentes grados de NIHL. Resultados: Los sujetos con hipoacusia se desviaron más claramente del desempe o normal cuando ejecutaron la prueba con ruido enmascarante alternativo, excepto en las condiciones de filtro pasa alto. La mayor distinción entre normoyentes y sujetos con NIHL en la prueba Earcheck fue con el ruido con filtro pasa-bajo. El uso de este tipo de ruido mejor la sensibilidad de la prueba Earcheck hasta llegar a un 95%. Conclusiones: El uso de ruido enmascarante con filtro pasa-bajo hace que la prueba de lenguaje en ruido sea más sensible para detectar NIHL en una fase inicial.     

Unilateral otosclerosis and noise-induced occupational hearing loss

Unilateral otosclerosis and noise-induced occupational hearing loss The interaction between noise-induced hearing loss and otosclerosis remains unclear and controversial. In the present study, the effect of chronic noise exposure was examined in 31 patients with unilateral otosclerosis. Consideration was given to hearing loss at specific frequencies, the influence of age, and the effect of the size of the air-bone gap. A small, though statistically significant, protective effect of otosclerosis was demonstrated at 4 kHz. This effect was maintained despite advancing age. An apparent inverse relationship was found between the amount of hearing loss and the size of the air-bone gap at 4 kHz, but multiple linear regression analysis suggested that this finding was contaminated by age effects.     

The protective effect of adrenocorticotropic hormone treatment against noise-induced hearing loss

Objective

NIHL is a common problem, and steroids are the most effective treatment option. In this study, we aimed to evaluate the protective effects of the synthetic adrenocorticotropic hormone (ACTH) analogues, which induce endogenous steroid secretion, against noise-induced hearing loss (NIHL) and to compare their effectiveness with that of steroid treatment.