Elucidation of the mechanism underlying the variation of the medial olivocochlear bundle reflex strenth

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K18066
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 61010:Perceptual information processing-related
• Research Institution: Chiba University
• Principal Investigator: Otsuka Sho 千葉大学, フロンティア医工学センター, 助教 (00776049)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: オリーブ蝸牛束 / 耳音響放射 / 音響暴露 / 騒音性難聴

Outline of Final Research Achievements

It has been reported that the medial olivocochlear reflex (MOCR) strength varies across individuals and is correlated with vulnerability of acoustic injury. To examine whether and how the acoustic exposure history leads to this inter-individual variation, the effects of the musical specialties were investigated. The factor of the musical speciality affected the strength of MOCR. It was caused mainly by the peculiarity of the violinists. Series of experimets conducted on non-musicians further revealed that MOCR strength was influenced by attentional state and expectation on an upcoming sound, and the MOCR strength significantly varied across individuals. These results suggest that the inter-individual variations in MOCR is caused by the difference in acoustic exposure histroy and cognitive processing ability.

Free Research Field

医工学

Academic Significance and Societal Importance of the Research Achievements

これまで，オリーブ蝸牛束反射の強いほど，騒音性難聴になりにくいことが示されてきたものの，その個人差が生じるメカニズムは明らかになってはいなかった．音響暴露の履歴と認知的処理がオリーブ蝸牛束反射の個人差の一因であることを示した本研究の成果は，騒音性難聴のなりやすさに個人差が生じるメカニズムの一端を解明するものである．得られた知見は，将来的にオリーブ蝸牛束の内耳保護機能を強化する手法の開発へと繋がり，騒音性難聴の根本的な予防に貢献できる可能性がある．