Assistive Listening Devices

Hearing aids can work wonders to improve how you understand speech. But certain conditions can be particularly troublesome, such as listening in groups, hearing in noisy surroundings, hearing a speaker more than a few feet away, and hearing in poor acoustic environments. Turning the volume up in these situations would result in turning up the background noise that you don't want to hear.

That's where assistive listening devices can help.

What are Assistive listening devices?

Assistive listening devices (ALDs) are amplification systems specifically designed to help people hear better in a variety of harsh listening conditions.

They can:

  • Help resolve background noise.
  • Mitigate the negative effect and sound disturbances of being far away from the sound source.
  • Eliminate the effect of reverberations in a room.

The primary purpose of an ALD is to enhance the listener's "signal to noise ratio." This means amplifying desired sounds (signals), and eliminating undesired sounds (noises).

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Assistive listening devices are particularly useful in public places where the sound source can be far from the listener, or there is substantial background noise such as:

  • meetings
  • colleges
  • political gatherings
  • places of worship
  • cinemas
  • restaurants
  • banks
  • public places such as airports or municipal buildings
  • watching TV with others
  • making phone calls

Types of assistive listening devices
This common ALD helps people watch TV at a level that doesn't disturb others in the household. A portable transmitter and a microphone are placed next to the TV. The sound that the microphone picks up is transmitted to a receiver worn by the listener, without any reduction in volume. These devices can carry over a considerable distance of up to 50 feet, with minimal distortion.