Development of an instrument for measuring OAE in the low frequency range (AMEOAE) and elucidation of the pathophysiology of low frequency sensorineural hearing loss

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K09698
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: Keio University
• Principal Investigator: okamoto yasuhide 慶應義塾大学, 医学部(信濃町), 客員講師 (10317224)
• Co-Investigator(Kenkyū-buntansha): 大塚 翔 千葉大学, フロンティア医工学センター, 助教 (00776049) ; 神崎 晶 慶應義塾大学, 医学部(信濃町), 講師 (50286556)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 耳音響放射 / 低音障害型難聴 / 内耳障害 / 感音難聴

Outline of Final Research Achievements

The purpose of this research was to establish a method for evaluating inner ear function at low frequencies using otoacoustic emissions.
Initially, we had considered a "detection method using the relative instantaneous phase and phase modulation with the stimulus as indices," that is, a measurement method to evaluate the outer hair cells by evaluating the phase modulation to the stimulus sound at each stimulus level, but it was not a stable measurement method.
However, it was not a stable measurement method. We finally devised a new measurement method, "a detection method using group delay as an indicator," which evaluates the function of the phase distortion caused by the phase characteristics of the auditory filter, which is reflected in the otoacoustic radiation in the form of group delay, to evaluate external hair cells. This method can provide stable results for the evaluation of external hair cells in the low frequency range.

Free Research Field

聴覚

Academic Significance and Societal Importance of the Research Achievements

急性低音障害型感音難聴は，突発的に耳閉塞感や耳鳴りなどを発症する低音域を中心とする感音難聴であり，年々増加傾向にある。2005年の厚生労働省急性高度難聴に関する調査研究班の疫学研究から，その発症頻度は人口100万人あたり428から657人と報告されており，急性感音難聴を来す疾患の中で最も多い。しかしこれまで内耳有毛細胞の障害の程度などの評価は全く出来なかった。今回の研究の目的はこのような低音障害型難聴の有毛細胞の障害を臨床の現場で評価が出来るようにする機器開発を目的としているため、今回の研究による測定法が確立されたことは今後の難聴評価に対して大きな意義があると考えている。