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:
“The hearing ear is always found close to the speaking tongue; and no genius can long or often utter anything which is not invited and gladly entertained by men around him.”
—Ralph Waldo Emerson (1803–1882)
“Men, forever tempted to lift the veil of the future—with the aid of computers or horoscopes or the intestines of sacrificial animals—have a worse record to show in these “sciences” than in almost any scientific endeavor.”
—Hannah Arendt (1906–1975)