Department of Human Science/Research Center for Applied Perceptual Science/Research and Development Center for Five-Sense Devices, Kyushu University, 4-9-1 Shiobaru, Minami-ku, 815-8540, Fukuoka, Japan.
School of Audiology and Speech Sciences, The University of British Columbia, 2177 Wesbrook Mall, Vancouver, BC V6T 1Z3, Canada.
Atten Percept Psychophys. 2021 Jul;83(5):1928-1934. doi: 10.3758/s13414-021-02292-3. Epub 2021 Apr 13.
Intelligibility of temporally degraded speech was investigated with locally time-reversed speech (LTR) and its interrupted version (ILTR). Control stimuli comprising interrupted speech (I) were also included. Speech stimuli consisted of 200 Japanese meaningful sentences. In interrupted stimuli, speech segments were alternated with either silent gaps or pink noise bursts. The noise bursts had a level of - 10, 0 or + 10 dB relative to the speech level. Segment duration varied from 20 to 160 ms for ILTR sentences, but was fixed at 160 ms for I sentences. At segment durations between 40 and 80 ms, severe reductions in intelligibility were observed for ILTR sentences, compared with LTR sentences. A substantial improvement in intelligibility (30-33%) was observed when 40-ms silent gaps in ILTR were replaced with 0- and + 10-dB noise. Noise with a level of - 10 dB had no effect on the intelligibility. These findings show that the combined effects of interruptions and temporal reversal of speech segments on intelligibility are greater than the sum of each individual effect. The results also support the idea that illusory continuity induced by high-level noise bursts improves the intelligibility of ILTR and I sentences.
研究了局部时间反转语音（LTR）及其中断版本（ILTR）对时间降级语音的可懂度。还包括了包含中断语音（I）的对照刺激。语音刺激由 200 个日语有意义的句子组成。在中断刺激中，语音片段与静音间隙或粉红噪声突发交替出现。噪声突发的水平相对于语音水平为-10、0 或+10 dB。对于 ILTR 句子，片段持续时间从 20 到 160 ms 不等，但对于 I 句子，持续时间固定为 160 ms。在 40 到 80 ms 的片段持续时间内，与 LTR 句子相比，ILTR 句子的可懂度严重降低。当 ILTR 中的 40-ms 静音间隙被 0 到+10 dB 的噪声取代时，可懂度会有显著提高（30-33%）。噪声水平为-10 dB 时对可懂度没有影响。这些发现表明，语音片段中断和时间反转的综合效应大于每个单独效应的总和。结果还支持了这样一种观点，即高强度噪声突发引起的虚幻连续性提高了 ILTR 和 I 句子的可懂度。
