Environmental Acoustics Laboratory, Graduate School of Engineering, Kobe University Rokko, Nada, Kobe 657-8501, Japan.
J Acoust Soc Am. 2011 Sep;130(3):1411-9. doi: 10.1121/1.3609122.
The acceptable range of speech level as a function of background noise level was investigated on the basis of word intelligibility scores and listening difficulty ratings. In the present study, the acceptable range is defined as the range that maximizes word intelligibility scores and simultaneously does not cause a significant increase in listening difficulty ratings from the minimum ratings. Listening tests with young adult and elderly listeners demonstrated the following. (1) The acceptable range of speech level for elderly listeners overlapped that for young listeners. (2) The lower limit of the acceptable speech level for both young and elderly listeners was 65 dB (A-weighted) for noise levels of 40 and 45 dB (A-weighted), a level with a speech-to-noise ratio of +15 dB for noise levels of 50 and 55 dB, and a level with a speech-to-noise ratio of +10 dB for noise levels from 60 to 70 dB. (3) The upper limit of the acceptable speech level for both young and elderly listeners was 80 dB for noise levels from 40 to 55 dB and 85 dB or above for noise levels from 55 to 70 dB.
本研究基于词语可懂度得分和听力困难度评价来调查言语声级作为背景噪声级函数的可接受范围。在本研究中，可接受范围被定义为最大程度提高词语可懂度得分且同时不会使听力困难度评价与最低评价相比显著增加的范围。对年轻成年和老年听众的听力测试表明：（1）老年听众的可接受言语声级范围与年轻听众的重叠。（2）对于噪声水平为 40 和 45dB（A 加权），对于噪声水平为 50 和 55dB，言语声级与噪声级的比为+15dB，以及对于噪声水平从 60 到 70dB，言语声级与噪声级的比为+10dB，年轻和老年听众的可接受言语声级的下限均为 65dB（A 加权）。（3）对于噪声水平从 40 到 55dB，年轻和老年听众的可接受言语声级上限均为 80dB，而对于噪声水平从 55 到 70dB，可接受言语声级上限为 85dB 或更高。
