Studies of speech intelligibility in classrooms

Abstract

The classroom is the place in which spoken language communication takes place to enable students to learn essential knowledge. Thus, the classroom can be defined as a communication channel for learning. My research is to focus on the special requirement and parameters placed on this communication channel by the listeners. The objective of my is to quantify the effects on the listeners in terms of their age, hearing status and background knowledge status. In addition, English, Cantonese and Mandarin proficiency on speech intelligibility in silent or noisy area is also examined to find out the signal-to-noise ratios that enable all students to obtain high intelligibility. The purpose of these studies is to apply different parameters such as "signal-to-noise ratio", "early decay time"(EDT), "speech transmission index"(STI) and "reverberation time"(RT) to predict the classroom characteristics. Besides, analysis of the younger generations for whom Cantonese, Mandarin and English are either their first or secondary language will be reported. Finally, various methods of estimating signal-to-noise ratios at different positions inside the classroom will be introduced, such as "ray tracing and image source method of computer simulation" and "Rapid Speech Transmission index"(RASTI) estimation in "Maximum Length Sequence System Analysis"(MLSSA), which predicts the intelligibility of different languages.