- 著者
- Ryosuke O. Tachibana Yasunari Sasaki Hiroshi Riquimaroux
- 出版者
- 一般社団法人 日本音響学会
- 雑誌
- Acoustical Science and Technology (ISSN:13463969)
- 巻号頁・発行日
- vol.34, no.4, pp.263-270, 2013-07-01 (Released:2013-07-01)
- 参考文献数
- 29
- 被引用文献数
- 1 11
In this study, we investigated how the temporal envelopes contribute to the recognition of isolated syllables, words, and sentences in noise-vocoded speech, under comparison with the influence of spectral resolution. The spectral and temporal resolutions of speech materials were systematically manipulated by a noise-vocoding technique. Japanese monomoraic syllables, meaningful and meaningless words, and sentences were used as test speech materials. The original speech sound was spectrally separated by a filter bank, and each spectral band was replaced with band noise, preserving its original temporal envelope. Spectral resolution was controlled by varying the number of spectral bands as 4, 8, or 16 bands. Temporal resolution was altered by smoothing the amplitude envelope using a low-pass filter with cut-off frequencies at 4, 8, or 16 Hz. Results demonstrated an increased dependence on temporal resolution in comparison with spectral resolution for the recognition of speech materials at higher structural levels (i.e., monosyllables, words, and sentences). This increased temporal dependence suggests that the temporal envelope in noise-vocoded sentences contained a greater amount of suprasegmental information, such as coarticulations, prosodies, and rhythms, in the original speech sound.