An ALD is a device that transmits sound directly to an individual who is wearing a sound receiver.
ALDs reduce problems associated with background noise in one on one and group communication.
By sending the sound signal directly to the individual, the ALD enables the individual to maximize their ability to hear and understand important sounds while reducing frustration associated with hearing unwanted background noises. An ALD works by transmitting sound through a microphone or public address system. FM radio signal, infrared light, and induction loop systems. FM systems transmit sound via radio waves. Infrared systems use lightwaves to send electrical signals to receivers that convert the electrical signals back to electrical energy and then sound.