Asahina N
Department of Otolaryngology, Showa University School of Medicine, Tokyo.
Nihon Jibiinkoka Gakkai Kaiho. 1994 Mar;97(3):401-13. doi: 10.3950/jibiinkoka.97.401.
In studying speech intelligibility in traffic noise, I was able to reproduce a sound field with considerable reality by reproducing both speech and traffic noises by the speaker method using a CD. As a result, the following conclusions were reached. 1) The influence of noise on speech intelligibility is similar for the single syllable and adult disyllable in normal persons. 2) The influence of the kinds of noises and changes with time in the sound pressure level on the intelligibility of the single syllable does not easily manifest itself in patients with sensorineural hearing loss. 3) The speech intelligibility depends largely on the blocking effect of the mid-high frequency components of the noise in both normal persons and patients with sensorineural hearing loss. 4) The intelligibility of the second sound of the adult disyllable is good in both normal persons and patients with sensorineural hearing loss. Furthermore, normal persons can understand a significant disyllable word to some extent by means of "uncertain understanding" even when they cannot hear each vowel and consonant clearly. 5) The intelligibility of the vowel is good in both normal persons and patients with sensorineural hearing loss. 6) As for the intelligibility classified by consonant in normal persons, the intelligibility of the nasal sounds (m, n) and voiced consonants (b, d, g, r, z) becomes low in the case of the S/N ratio being poor. 7) In patients with sensorineural hearing loss, the intelligibility of the bulldozer noise was the lowest, followed by motorway noise among the noises applied. The frequency spectrum distribution of the former consisted mainly of mid-high frequencies of 1 kHz or more. A serrated change with an amplitude of about 6 dB, 2 Hz was noted at the sound pressure level. A sine wave-like change with an amplitude of about 7 dB, 1 Hz was recognized at the sound pressure level of the latter. These are considered to be factors which account for a decline in intelligibility. The present study is part of an experiment I conducted at a sound field using TY-89. The results of this experiment suggest that the frequency spectrum intelligibility of noise as well as time-dependent changes in the sound pressure level of the noise exert an influence on communication disruption in patients with sensorineural hearing loss.
在研究交通噪声中的语音清晰度时，我通过使用CD采用扬声器法重现语音和交通噪声，成功重现了具有相当真实感的声场。结果得出了以下结论。1）在正常人中，噪声对单音节和成人双音节语音清晰度的影响相似。2）对于感音神经性听力损失患者，噪声种类和声压级随时间的变化对单音节清晰度的影响不易显现。3）正常人和感音神经性听力损失患者的语音清晰度在很大程度上取决于噪声中高频成分的掩蔽效应。4）成人双音节中第二个音的清晰度在正常人和感音神经性听力损失患者中都很好。此外，即使正常人不能清楚地听到每个元音和辅音，他们也能通过“不确定理解”在一定程度上理解有意义的双音节词。5）元音的清晰度在正常人和感音神经性听力损失患者中都很好。6）对于正常人按辅音分类的清晰度，在信噪比差的情况下，鼻音（m、n）和浊辅音（b、d、g、r、z）的清晰度会降低。7）在感音神经性听力损失患者中，在所应用的噪声中，推土机噪声的清晰度最低，其次是高速公路噪声。前者的频谱分布主要由1kHz及以上的中高频组成。在声压级上观察到幅度约为6dB、频率为2Hz的锯齿状变化。在后者的声压级上识别出幅度约为7dB、频率为1Hz的正弦波状变化。这些被认为是导致清晰度下降的因素。本研究是我在使用TY - 89的声场中进行的实验的一部分。该实验结果表明，噪声的频谱清晰度以及噪声声压级随时间的变化对感音神经性听力损失患者的沟通障碍有影响。
