TY - JOUR
T1 - Phonemic restoration of interrupted locally time-reversed speech
T2 - Effects of segment duration and noise levels
AU - Ueda, Kazuo
AU - Ciocca, Valter
N1 - Funding Information:
The authors would like to thank Hikaru Eguchi for programming in LiveCode, Hirotatsu Koga for running the experiment, Kaisei Shiraki and Nozomi Inui for running preliminary experiments, and Yoshitaka Nakajima and Gerard B. Remijn for valuable discussion. Y.N. also provided computer program routines in the J language. Wolfgang Ellermeier and two anonymous reviewers provided helpful suggestions for improving this manuscript. This work was supported by the Japan Society for the Promotion of Science, KAKENHI Grant Numbers JP17K18705 and JP19H00630.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/6/19
Y1 - 2021/6/19
N2 - 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.
AB - 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.
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U2 - 10.3758/s13414-021-02292-3
DO - 10.3758/s13414-021-02292-3
M3 - Article
C2 - 33851359
AN - SCOPUS:85104505446
SN - 1943-3921
VL - 83
SP - 1928
EP - 1934
JO - Attention, Perception, and Psychophysics
JF - Attention, Perception, and Psychophysics
IS - 5
ER -