A Comparison of Band-Importance Function and Transfer Function Using Clear Speech and Conversational Speech

Abstract

Purpose This study compared band-importance function (BIF) and transfer function (TF) derived using clear and conversational speech. Methods There were 156 participants in this study: 78 for the clear speech group and the others for the conversational speech group. The data used to derive BIF and TF were obtained using the same procedure as the previous study. Sentences from Speech Perception In Noise test were used as stimuli. Intelligibility scores were measured via 42 filters at five signal-to-noise ratios. The BIFs and TFs for clear and conversational speech were derived using a nonlinear optimization procedure. Then those for the different production methods were compared. Results The BIF and TF for different production methods have different characteristics. For BIF, the highest weights of importance for clear speech ranged between 200 Hz and 400 Hz and the highest weights for conversational speech ranged between 510 Hz and 770 Hz. The maximum different band-importance weight for the two production methods was 1.92%p at a center frequency of 2,150 Hz. The TF for clear speech was steeper than the TF for conversational speech. Conclusion The results of the current study provide information on the degree to which the clear speech is more intelligible according to the listener’s audibility compared to that for conversational speech. Audiologists and hearing professionals will use this information, when considering the communication strategy for people with hearing loss. Key Words: Speech intelligibility index, Clear speech, Band-importance function, Transfer function, Speech intelligibility 중심 단어: ì–´ìŒëª ë£Œì§€ìˆ˜, ëª ë£Œì–´ìŒ, 주파수중요함수, ì „ë‹¬í•¨ìˆ˜, 어음인지도