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:
“It was my thirtieth year to heaven
Woke to my hearing from harbor and neighbor wood”
—Dylan Thomas (1914–1953)
“Be sure that you give the poor the aid they most need, though it be your example which leaves them far behind. If you give money, spend yourself with it, and do not merely abandon it to them.”
—Henry David Thoreau (1817–1862)