ear trumpet

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A horn-shaped device formerly used to direct sound into the ear of a hearing-impaired person.

from The Century Dictionary.

• noun An apparatus for collecting sound-waves and conveying them to the ear, used chiefly by the deaf.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A conical shape designed to channel sound to the apex, which was placed in the ear, to serve as a hearing aid.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a conical acoustic device formerly used to direct sound to the ear of a hearing-impaired person