a compact electronic amplifier worn to improve one's hearing, usually placed in or behind the ear.
Origin of hearing aid
First recorded in 1920–25
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
British Dictionary definitions for hearing aid
a device for assisting the hearing of partially deaf people, typically consisting of a small battery-powered electronic amplifier with microphone and earphone, worn by a deaf person in or behind the ear
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Medicine definitions for hearing aid
A small electronic apparatus that amplifies sound and is worn in or behind the ear to compensate for impaired hearing.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.