Evaluation standards for speech intelligibility in indoor sound fields have been studied for many years. In an auditorium, the acoustic quality and intelligibility of speech is influenced by the number and duration of sound reflections. The Rapid Speech Transmission Index (RASTI) is derived from a simple measurement for the evaluation of a sound field. The purpose of this study is to understand the relationship between the Chinese articulation standard and the RASTI ratio in Taiwan. The compounded vowels of single Chinese syllables were used to approximate 108 phonemics to build the test table for scoring intelligibility, according to the Chinese articulation standard in the Taiwan area. In this research, we surveyed 8 sound fields (with back ground noise less than NC-40) in auditoriums located in Taiwan. The results show a good correlation between the RASTI ratio and the intelligibility scores(r=0.90, R^2=0.82). Furthermore, we found the intelligibility score for some special Chinese syllables have inner differences (p<0.001) in certain measurement tables.
Evaluation standards for speech intelligibility in indoor sound fields have been studied for many years. In an auditorium, the acoustic quality and intelligibility of speech is influenced by the number and duration of sound reflections. The Rapid Speech Transmission Index (RASTI) is derived from a simple measurement for the evaluation of a sound field. The purpose of this study is to understand the relationship between the Chinese articulation standard and the RASTI ratio in Taiwan. The compounded vowels of single Chinese syllables were used to approximate 108 phonemics to build the test table for scoring intelligibility, according to the Chinese articulation standard in the Taiwan area. In this research, we surveyed 8 sound fields (with back ground noise less than NC-40) in auditoriums located in Taiwan. The results show a good correlation between the RASTI ratio and the intelligibility scores(r=0.90, R^2=0.82). Furthermore, we found the intelligibility score for some special Chinese syllables have inner differences (p<0.001) in certain measurement tables.