A hearing aid is an electroacoustic device which typically fits in or behind the wearer's ear, and is designed to amplify and modulate sound for the wearer. Earlier devices, known as ear trumpets or ear horns, were passive funnel-like amplification cones designed to gather sound energy and direct it into the ear canal. Similar devices include the bone anchored hearing aid, and cochlear implant.
Read more about Hearing Aid: Types, Indications, Adjustment, Purchase Costs, Batteries
Famous quotes containing the words hearing and/or aid:
“To-night she will spread her brown hair on his pillow,
But I shall be hearing the harsh cries of wild fowl.”
—Patrick MacDonogh (1902–1961)
“I know not how to aid you, save in the assurance of one of mature age, and much severe experience, that you can not fail, if you resolutely determine, that you will not.”
—Abraham Lincoln (1809–1865)