de Almeida S I, Albernaz P L, Zaia P A, Xavier O G, Karazawa E H
Departamento de Otorrinolaringologia e Distúrbios da Comunicação Humana, Universidade Federal de São Paulo, Escola Paulista de Medicina.
Rev Assoc Med Bras (1992). 2000 Apr-Jun;46(2):143-58.
To evaluate the clinical and audiometric characteristics of occupational hearing loss induced by noise, according to age and time of exposition in years.
222 patients with occupational sensorineural hearing loss induced by noise were studied retrospectively, correlating the auditive clinical claims, alterations of audiometric thresholds at frequencies of 250 Hz to 8000 Hz, speech discrimination indicator with age and time of exposure. As a control group were used the audiometric threshold of a population of same medium age, without morbid antecedents of hearing illness, as preconized by ISO 1999 (1990). The group were divided into subgroups and three decades of exposure were analyzed.
It was verified that the clinical claims of hipoacusia increases according to the age and time of exposure. The frequency of tinnitus is constant. The audiometric thresholds in the second decade of exposure present variations that depend on the age. The several audiometric curves are parallel, but they are not horizontal. The worst thresholds were found in the high frequencies from 3000 Hz to 8000 Hz, as a clinical and physiopathological consequences of the commitment of basal areas of cochlea. The speech discrimination showed to be worst according to the increase of age and time of exposure.
Patients with hearing loss disacusia induced by occupational noise present characteristic audiometric thresholds that vary according to age and time of exposure to noise. These characteristics defined and resumed in audiometric curves can constitute a standard of comparison, evaluation and control for exposed populations.
根据年龄和暴露年限评估噪声所致职业性听力损失的临床和听力特征。
对222例噪声所致职业性感音神经性听力损失患者进行回顾性研究，将听觉临床主诉、250Hz至8000Hz频率的听力阈值变化、言语辨别指标与年龄和暴露时间相关联。按照ISO 1999（1990）的规定，以年龄相仿、无听力疾病病史人群的听力阈值作为对照组。将该组患者分为亚组并分析三个暴露十年期的情况。
证实听力减退的临床主诉随年龄和暴露时间增加。耳鸣频率恒定。暴露第二个十年期的听力阈值变化取决于年龄。多条听力曲线平行，但并非水平。在3000Hz至8000Hz高频段发现最差阈值，这是耳蜗基底区域受累的临床和生理病理后果。言语辨别能力随年龄和暴露时间增加而变差。
职业噪声所致听力损失患者呈现出根据年龄和噪声暴露时间而变化的特征性听力阈值。这些在听力曲线中得以界定和概括的特征可构成暴露人群的比较、评估和控制标准。
