Listening Devices: Part 1.1- Hearing Aid Technology

This is a supplementary post to our Listening Devices: Part 1- Hearing Aids.

All hearing aids are not created equal! Here is a run-down of the technological add-ons available. Please note: not all of these are available for every style of aid.

Digital/Analog
Analogue hearing aids work by converting sound waves into electrical waves, which gives an accurate sound reading. Digital hearing aids are more technologically advanced and produce an exact duplication of sound. As may be expected, the sound quality provided by digital hearing aids is much higher than that provided by analogue hearing aids. Of course, this boost in quality is reflected in a boost in price!

On-Off Control
As you may have guessed, this turns the hearing aid on or off. Sometimes this is incorporated into the volume control wheel. When an on-off switch is not present, the hearing aid is activated by inserting the battery.

Audio Input
This allows an audio signal directly from the signal source (like a television or radio). It requires an audio boot which is most commonly found on a BTE hearing aid.

Microphones
Omnidirectional: This type of microphone picks up sound from all directions.

Unidirectional (sometimes just called "directional"): This type of microphone picks up sound coming from a specific direction (often directly in front of the user).

Some newer hearing aids are equipped with both types of microphones and the user can choose to switch between them depending on the circumstances.

Telecoil (a.k.a. T-coil or Audiocoil)
This is an induction coil within a hearing aid that enhances telephone communication. It functions by bypassing the hearing aid microphone. It is able to pick up the electromagnetic signals emitted by the telephone receiver. Use of a telecoil minimizes acoustic feedback, providing better-quality sound. Some hearing aids have an on-off switch for the telecoils and some will automatically switch in response to holding the telephone to the ear.

Volume Control
This allows the user to adjust the level of the amplification signal he/she is receiving.

Remote Control
This can be used to adjust the properties of the hearing aid (such as microphone direction). It can also be used to switch hearing channel, adjust the volume, and to turn it on and off. This is very helpful with a small device.