Assistive listening device

An assistive listening device (ALD) is part of a system used to improve hearing ability for people in a variety of situations where they are unable to distinguish speech in noisy environments.

However, if the sound is too distorted by the time it reaches the listener, even the best hearing aids will struggle to unscramble the signal.

Assistive listening devices offer a more adaptive alternative to hearing aids, but can be more complex and cumbersome.

A common usage is to aid people who are hard of hearing (HOH) by amplification and providing a better signal to noise ratio (SNR).

There are also other consumer ALDs such as alarm clocks with bed shakers, amplified stethoscopes, baby monitors, and flashing door bell indicators.