The cartilage conduction hearing aid
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The hearing aid attached to an ear
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Hiroshi Hosoi, president of Nara Medical University
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Rion Co Ltd released a cartilage conduction hearing aid Nov 13, 2017.

The hearing aid eliminates the need to put an earphone in an earhole and is targeted at hearing-impaired people who cannot use normal hearing aids due to atresia of external auditory meatus, a large amount of ear discharge, etc.

The cartilage conduction hearing aid consists of the main unit (hearing aid) and an oscillator. The oscillator, which is used in place of an earphone, is attached to the cartilage part of the entrance of the external auditory canal. And sound amplified by the main unit is transmitted as a vibration so that the user can hear the sound.

The fact that sound can be heard by cartilage conduction was found in 2004 by Hiroshi Hosoi, president of Nara Medical University, and others. They conducted a joint research on cartilage conduction with Rion and released the hearing aid this time with confidence.

Ear functions as speaker

When the oscillator is used to vibrate the cartilage part of the entrance of the external auditory canal, the vibration is transmitted to the inside of the external auditory meatus, which is made of cartilage, generating air-conducted sound. In other words, the user's ear is used as a speaker (sound source), Hosoi said. The air-conducted sound moves the cells of the internal ear, making it possible to hear the sound.

Original Japanese article