한국어 기반 클리어스피치와 일반 발화에 따른 어음역동범위 비교

Comparison of Dynamic Range of Clear Speech and Conversational Speech in Korean

Purpose: Speech dynamic range (DR) represents the range between maximum and minimum levels of speech across frequencies. The DR has been considered as an important factor in speech intelligibility. This study aimed to identify any differences in DR between Korean clear speech and conversational speech. Methods: A standardized sentence stimuli were recorded with manners of conversational and clear speech. The DR was quantified using cumulative histogram levels based on recorded voice data from 35 native Korean female participants with normal hearing. Then, the DRs were compared according to the production method after level normalization at 65 dB sound pressure level. Results: Maximum levels in the DR for Korean clear speech were greater than for Korean conversational speech in most frequency bands. Especially, differences of the DR between conversational speech and clear speech were between 0.47 dB (center frequency of 570 Hz) and 2.96 dB (center frequency of 1,170 Hz). Conclusion: The results of this study suggest that the DR for Korean clear speech has acoustical characteristics that are favorable to speech intelligibility, compared to the DR for conversational speech.