Can You Hear Me Now?
From: Proto - Winter 2007 - page 13

For centuries the hard of hearing retied on devices that looked more Like
jazz instruments than today's dime-size hearing aids. The construction of
those early devices, such as the ear trumpet, was decidedly low-tech. 

More unusual contraptions emerged throughout the nineteenth century, with
clever designs to conceal hearing aids in objects such as centerpieces and
canes. The acoustic urn channeled sound from all corners of a room while
disguising itself as a tabtetop decoration. The first electrical hearing aids
were developed in the late 1800s using a carbon microphone, but it was not
until the 1930s and l940s that a portable device was developed.  

In recent years hearing devices have grown smaller but possess improved sound
quality. One lingering problem, however, is the feedback and static that
result when a wearer uses a cellular phone. One company has solved the
problem by adding Bluetooth to turn the aid itself into a phone.

Links:
Acoustic Urn
http://www.vard.org/mono/ear/portfoli.htm