关键词: 言语可懂度, 单音节词, 双音节词, 语句, 语音传输指数（STI）

Abstract: Speech intelligibility is an important indicator for evaluating the acoustic quality of lecture rooms and auditoria. There are various subjective evaluation methods for speech intelligibility, but their evaluation results for lecture rooms and auditoria vary significantly, with unclear applicability. The relationship curves between speech intelligibility scores and the speech transmission index(STI) were established under 24 architectural acoustic conditions. Then, through sensitivity analysis, correlation analysis, and relational analysis, the applicability of 8 subjective evaluation methods of speech intelligibility belonging to 3 categories was studied. The results show that:(1)Monosyllable word curves exhibit moderate sensitivity(slope:11.7~14.8% per 0.1 STI unit in the 20–80% linear range). Disyllable word and sentence curves show higher initial sensitivity under poor listening conditions but rapid decline in sensitivity with ceiling effects. (2)Open-set phoneme-balanced mono-and disyllable word and daily sentence strongly correlate with subjective perception (r=-0.78 to -0.88), outperforming closed-set rhyme monosyllable and sentence(r=-0.50 to -0.69). The correlation of open-set monosyllable word decreases relatively slowly with the improvement of listening conditions. (3) Monosyllable word rank highest in comprehensive relational degree with subjective-objective parameters, while disyllable word and sentences rank lower. The 75 phoneme-balanced monosyllable word demonstrate optimal applicability due to its wide moderate-sensitivity range, strong perceptual correlation, and top-ranked comprehensive performance. The results can provide a reference for the selection of subjective evaluation methods for speech intelligibility in lecture rooms and auditoria.

Key words: speech intelligibility, monosyllable word, disyllable word , sentence, speech transmission index(STI)