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

首先对群马县高中生使用耳机立体声引起的噪声性听力损失进行初步问卷调查，询问其使用耳机的频率、时间和响度。参与问卷调查的人数分别为男性2311人，女性301人。结果显示，听到耳机立体声音量更大的学生往往被其他人认为听力灵敏度较低。从消费者健康的角度来看，有必要进行广泛的流行病学调查，因为便携式耳机立体声在相对较短的时间内变得如此流行。结果表明，听力阈值在1000赫兹时有所增加，尽管听力水平在1990年没有测量过。建议测量听力水平在4000赫兹，这是噪音引起的听力损失最敏感的频率。然后，为了评估耳机立体声使用与阈值升高之间的关系，对两所高校的122名学生进行了听力水平测试。通过分析，作者发现耳机的使用与听力水平之间没有显著的关系，这可能是由于耳机的使用频率较低。结果可能只反映了部分相关性。建议再次进行评估，加入更频繁使用耳机立体声的用户的数据。

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.