Effects of length perception in reverberant environments on phoneme discrimination

2023 Fiscal Year Final Research Report

• Project/Area Number: 19K23083
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0102:Literature, linguistics, and related fields
• Research Institution: Showa University (2022-2023); Sophia University (2019-2021)
• Principal Investigator: Osawa Eri 昭和大学, 教養部, 講師 (40845351)
• Project Period (FY): 2019-08-30 – 2024-03-31
• Keywords: 音声知覚 / 室内音響 / 非母語話者

Outline of Final Research Achievements

In the current study, I investigated the perception of speech sounds in reverberant conditions, specifically focusing on the effects of length perception on the identification of speech sounds. I conducted experiments that examined the discrimination between long and short vowels in Japanese (such as "ie" (house) vs. "iie" (no)) under reverberant conditions. The participants included native Japanese listeners and learners of Japanese, and I compared the performance of these two groups. The results indicated that reverberation affected even the performance of native Japanese listeners, with a significant decline observed under long reverberation conditions. In contrast, learners were found to be significantly affected even by short reverberation.

Free Research Field

音声学、音韻論、音響学

Academic Significance and Societal Importance of the Research Achievements

残響は以前より言語明瞭度を下げるものとして問題視されていたが、騒音下知覚に比べ行われている研究が少ないのが現状であった。またすでに行われている研究も英語を対象としたものが多く、日本語に焦点を当てた研究はほとんど見られなかった。本研究は日本語の特徴を生かし、時間長に着目することで残響への我々の対処能力の一端を明らかにすることができた。
また、残響は災害時の放送を聞き取りにくくする原因の一つと考えらえているため、この研究の成果がそうした音声の改善につながれば社会的貢献度も大きい。