低信噪比时混响时间对汉语单音节识别率的影响

摘要

目的：在模拟教室环境下行混响时间处理过的单音节词言语识别率测试，探讨最佳混响时间范围，为教室声学环境标准制定提供参考依据。方法用音频编辑软件将5张单音节词表的混响时间依次设为0.5、0.9、1.3、1.7和2.1 s，在隔声室内-5 dB HL信噪比条件下模拟教室环境，对20名健听青年行5张词表的言语识别率测试，并对结果进行分析。结果混响时间为1.3 s时言语识别率最大；经组间比较，最佳混响时间范围是0.9～1.3 s。结论应关注教室混响时间的设计与汉语普通话言语识别的关系。%Objective To study the influence of different reverberation time(RT) on Chinese monosyllable recognition rate and to explore the optimum reverberation time in order to provide a theoretical evidence for the development of standards for the classroom acoustic environment in China.Methods The reverberation time of the 5 monosyllable lists was set to 0.5 s, 0.9 s, 1.3 s, 1.7 s and 2.1 s respectively by using Cool Edit Pro 2.1 Sound editing software. 20 subjects received the Chinese monosyllable recognition test in the soundproof room with SNR at -5 dB imitating classroom noise environment and the data obtained were statistically analyzed.Results The maximum monosyllable recognition rate was obtained when the RT was 1.3 s. There was no significant difference in the recognition rate between RT 0.9 s and 1.3 s, but the recognition rate of 1.3 s was significantly higher than that of 1.7 s (P<0.05), 0.5 s and 2.1 s (P<0.01). The optimum range of reverberation time was 0.9-1.3 s.Conclusion The relationship between the design of classroom reverberation time and Mandarin Chinese speech recognition should be highlighted.