Sometimes, people with poor hearing can benefit from an assistive listening device (ALD) rather than a hearing aid. ALDs might also help improve the listening experience for current hearing aid users. Rather than amplifying sounds, as hearing aids do, ALDs work by separating speech from background noise, making them especially helpful in situations where distance, poor acoustics or noisy backgrounds are a factor.
There are several different styles and types of ALDs. These include:
- FM systems. FM systems utilize radio signals to transmit amplified sounds directly to a hearing impaired individual’s hearing aids or cochlear implants. They consist of a trio of components: a microphone, transmitter and receiver. FM systems are often used in classroom settings, places of worship, restaurants and movie theaters.
- Personal amplifiers. Personal amplifiers are smaller FM systems that are used in places where radio signals are less effective—outdoors, in the car, at home. The microphone is usually built directly into the unit and may be directional, allowing the user to aim it toward the sound source.
- Infrared systems. Infrared systems are similar to FM systems but rely on infrared light instead of radio signals to transmit sound. Because infrared light cannot pass through walls, these systems can be used in places where multiple broadcasts might otherwise be an issue, or where confidentiality is important. Courtrooms and multiplex theaters are popular choices for infrared systems.
- Induction loops. Induction loops, or hearing loops, use electromagnetic energy to transmit sounds directly to hearing aids or cochlear implants through tiny built-in receivers known as telecoils. Induction loop systems are often found in public facilities such as airports, classrooms and places of worship. They consist of an amplifier and a loop of wire that work in tandem to broadcast signals to the user’s device.