Suppression of feedback problem in cartilage conduction hearing aids

2020 Fiscal Year Final Research Report

• Project/Area Number: 17K11339
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Nara Medical University
• Principal Investigator: Nishimura Tadashi 奈良県立医科大学, 医学部, 講師 (60364072)
• Co-Investigator(Kenkyū-buntansha): 細井 裕司 奈良県立医科大学, 医学部, その他 (80094613) ; 下倉 良太 大阪大学, 基礎工学研究科, 准教授 (90455428)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Keywords: 補聴器 / 外耳道閉鎖症 / 伝音難聴 / 軟骨伝導 / 骨導 / 聴覚 / ハウリング

Outline of Final Research Achievements

Feedback problem which can restrict the output level of hearing aids and its management methods were investigated in cartilage conduction (CC) hearing aids. The mechanism underlying the feedback problem for CC hearing aids were not only amplified signal leaking from the ear canal, which is the same manner as that for air conduction hearing aids, but also the transducer slipping induced by powerfully vibrations at high signal input level, which can generate airborne sound to flow back to the microphone. The latter mechanism is considered to be unique to CC hearing aids. This unique feedback problem occurred easily when the coupling condition of the transducer to the ear was unstable. To manage this feedback problem, the transducer should be placed on the flat region, and fixed stably.

Free Research Field

耳鼻咽喉科

Academic Significance and Societal Importance of the Research Achievements

軟骨伝導補聴器は日本発の新しい補聴器である。外耳道閉鎖症など既存の補聴器では対応が難しかった症例で、非侵襲で良好な装用効果が得られることから急速に普及が進んでいる。補聴器の装用効果を制限する重要な問題の１つにハウリングがあるが、軟骨伝導補聴器についても同じである。本研究は軟骨伝導補聴器で生じる特有のハウリングを解明し、その対処法を明らかにすることで補聴器の効果を高めることを可能とした。