Improvement of speech articulation in a noisy environment by wearing earplugs

通过佩戴耳塞改善嘈杂环境中的言语清晰度

• 批准号: 15560046
• 负责人: KUMAGAI Masazumi
• 金额: $ 1.79万
• 依托单位: Sendai National College of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560046/
• 关键词: earplug; speech articulation; noise; degree of sound insulation; threshold of hearing

This research was undertaken because of the theory that speech articulation in a noisy environment might be improved by wearing earplugs because earplugs could decrease the level of a specific range of a frequency composition of the noise.First, monosyllable articulation tests were carried out in an environment which was dominated by high frequency components with the variable of whether subjects wore JIS Type 2 earplugs or not. In these tests, sound pressure levels of the noise were set to levels between 65 dB and 85 dB, and sound pressure levels of monosyllables were set to levels between 0 dB and -10dB which referred the sound pressure level of the noise, that is, signal to noise ratios were between 0 and -10 dB. The results showed that the monosyllable articulations did not relate to wearing earplugs.Next, on the assumption of hard environmental noise, monosyllable articulation test was carried out exposing white noise of 95 dB SPL. In this test, monosyllables were set to 90 dB SPL, that is, signal to noise ratio was -5dB. In the noise at this sound pressure level, the acoustic reflex must be caused. In this test, JIS Type 1 earplugs which can insulate broad band sound were used. The results showed that monosyllable articulation obviously improved when the subjects wore earplugs.The conclusions of this research are as follows.1.In the noise of sound pressure level in which the acoustic reflex is caused, our hearing system can be protected by wearing earplugs, moreover, our speech articulation can be improved.2.In the noise of sound pressure level that is lower than the situation above, the difference of the speech articulation by wearing earplugs is not observed. This means that the speech articulation doesn't decrease even if the subject wears earplugs.

本研究是基于戴耳塞可以降低噪声的特定频率成分的水平，从而可以提高噪声环境下的语音清晰度的理论而进行的。首先，在以高频成分为主的环境中，以是否戴JISType 2耳塞为变量，进行单音节清晰度试验。在这些测试中，噪音的声压级被设定在65分贝至85分贝之间的水平，而单音节的声压级被设定在0分贝至-10分贝之间的水平，这是指噪音的声压级，即信噪比在0至-10分贝之间。结果表明，单音节清晰度与戴耳塞无关。其次，在强噪声环境下，暴露于95 dB SPL的白色噪声中进行单音节清晰度测试。在该测试中，单音节设置为90 dB SPL，即信噪比为-5dB。在这种声压级的噪声中，必然会引起声反射。在该试验中，使用能够隔离宽带声音的JIS 1型耳塞。研究结果表明，在引起声反射的声压级噪声中，戴耳塞不仅可以保护听力系统，而且可以提高语音清晰度;在声压级低于上述声压级的噪声中，戴耳塞可以提高语音清晰度，没有观察到佩戴耳塞的语音清晰度的差异。这意味着即使受试者戴上耳塞，语音清晰度也不会降低。