Integration mechanisms of speech perception under noisy environments

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K11959
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 61010:Perceptual information processing-related
• Research Institution: Aichi Shukutoku University (2022-2023); Waseda University (2021)
• Principal Investigator: Kobayashi Maori 愛知淑徳大学, 健康医療科学部, 教授 (90451632)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 音声知覚 / 雑音環境下 / 音韻修復現象

Outline of Final Research Achievements

We examined the effects of bandwidth of speech disappearance on the phonemic restoration（PR） using professional announcers’ speech and non-professional speakers’ speech . As a result, it was shown that in the announcers’ speech, the PR occurs even when information in the 250-4000 Hz frequency band is lost. It was found that the rates with acoustic features spanning high and wide frequency bands were higher in the announcers’ speech. This suggests that elements in the high-frequency band serve as phonemic cues only when noise added. Additionally, to examine the impact of the loss of frequency bands below 250 Hz, we investigated the PR by manipulating these bandwidths. This result indicates that, although the fundamental frequency is not considered a direct cue for phonemic perception in previous studies, it plays an important role in integrating fragmentary acoustic features.

Free Research Field

実験心理学

Academic Significance and Societal Importance of the Research Achievements

本研究では、雑音環境下でも頑健な音声は雑音によって知覚的に音韻が修復される音声であると考え、音韻修復現象を用いて検討した。その結果、頑健な音声では幅広い周波数帯域にわたって音声情報が消失したとしても知覚的に音韻修復されることがわかった。残余成分に着目すると、これまで音韻の直接的な手がかりと考えられてこなかった高周波数成分や基本周波数成分が音韻修復に関わっていることが示唆された。むしろ、これらの周波数成分は断片的な音韻情報を統合するための手がかりとなるのではないかと考えられる。このことは雑音下での音声メカニズムを検討する上で情報統合メカニズムの必要性を示唆するものといえる。