Fundamental Research on the Hearing Loss by the Use of Headphone Stereo

首先，对群马州高中生使用耳机立体声所致噪声性听力损失进行了初步问卷调查，询问耳机使用的频率、周期和响度。回答问卷的人数为2,311，2,010名男性和301名女性。结果显示，耳机立体声音量越大的学生，其他人表示听力越差的学生越多。从消费者健康的角度来看，便携式耳机立体声音响在相对较短的时间内变得如此流行，需要进行广泛的流行病学调查。结果表明，1000赫兹的听力阈值有所提高，尽管在1990年没有测量听力水平。建议在噪声性听力损失最敏感的4000赫兹处测量听力水平，然后对两所高校的122名学生进行听力水平测试，以评估耳机立体声的使用与听阈提高之间的关系。从分析中，作者没有发现耳机使用与听力水平之间的显著关系，这可能是因为使用耳机的频率较低。结果可能只反映了部分相关性。建议再加上耳机立体声频次较高的用户数据再做评估。

At first, a preliminary questionnaire survey of noise-induced hearing loss by the use of headphone stereo was conducted, which was applied to high school students in Gunma Prefecture asking the frequencies, periods and loudness of the headphone use. The number of subjects responded to the questionnaire was 2, 311, 2, 010 males and 301 females. The result revealed that the students who heard the headphone stereo at louder volume were indicated more often by the others to have a lower hearing acuity.From the view point of the consumer health, it is needed to conduct an extensive epidemiological survey, as the portable headphone stereo has become so popular within relatively shorter time. The results suggest an increased threshold of hearing at 1, 000 Hz, though the hearing level was not measured in 1990. It is recommended to measure the hearing level at 4, 000 Hz, which is the most sensitive frequency of noise-induced hearing loss.Then, in order to evaluate the association between the use of headphone stereo and increase of threshold, 122 students in two colleges were measured of the hearing level. From the analysis, the authors could find no significant relation between the headphone use and the hearing level, which may be due to less frequent headphone use. There may be a possibility that the results reflected only a partial correlation. It is recommended that the evaluation should be made again adding the data of more frequent headphone stereo users.