Szanto C, Ionescu M
Institut für Hygiene und Offentliches Gesundheitswesen, Cluj-Napoca, SR Rumänien.
Z Gesamte Hyg. 1990 Jan;36(1):44-7.
Hearing threshold level (HTL) in miners, was determined after six years interval characterized by the same noise exposure. An attempt was made to establish the prognosis regarding the hearing losses extent and the time interval involved in the occurrence of these modifications in the subjects applying the HTL values. 132 workers (miners and miner apprentices) underwent audiometrical examinations, after 6 years interval in the same testing conditions. To evaluate the vibrations possible effects on the HTL, the results registered in a group of workers exposed solely to noise (n = 33)-identical continuous equivalent level/week-were compared to those found in miners. According to age range and the duration of noise exposure, the yearly mean rate for both the low (500-2000 Hz) and high frequencies (2-8 kHz), were calculated based on the hearing threshold differences. The miners, simultaneously exposed to noise and vibration presented yearly decreased HTL values (up to 2000 Hz), as against the subjects exposed solely to noise. The prognosis indicates that in a miner with a duration of exposure above 21 years and/or a mean age of 38, one may expect a loss of the HTL exceeding 30 dB at 4 kHz.
在相同噪声暴露情况下，间隔六年测定矿工的听阈水平（HTL）。尝试依据HTL值确定受试者听力损失程度的预后情况以及这些变化发生的时间间隔。132名工人（矿工和矿工学徒）在相同测试条件下间隔6年后接受了听力检查。为评估振动对HTL的可能影响，将仅暴露于噪声的一组工人（n = 33，相同的连续等效水平/周）的测试结果与矿工的测试结果进行比较。根据年龄范围和噪声暴露时长，基于听阈差异计算低频（500 - 2000Hz）和高频（2 - 8kHz）的年均变化率。与仅暴露于噪声的受试者相比，同时暴露于噪声和振动的矿工每年的HTL值下降（高达2000Hz）。预后表明，对于暴露时长超过21年和/或平均年龄为38岁的矿工，预计其在4kHz时HTL损失超过30dB。
