Assistive Listening Device

Any device designed to improve audibility for a person with hearing loss, beyond or in addition to a hearing aid or cochlear implant. Common examples include personal amplifiers, FM and radio-frequency systems, infrared systems, and induction loop (hearing loop) systems installed in public venues. ALDs reduce the effects of background noise, distance, and reverberation by transmitting sound directly from a source — such as a lecturer's microphone, a television, or a theatre's sound desk — to the listener's ear or to a telecoil in their hearing device. In accessibility practice, ALDs are commonly required under venue-accessibility standards for theatres, places of worship, and public meetings.