Assistive Listening Devices
Assistive listening devices (ALDs) are portable systems that people with hearing disabilities can use to help them understand speech and other sounds more easily.
Often considered a type of personal amplifier, ALDs can be used as standalone devices or may be paired with hearing aids to improve their effectiveness.
ALDs are beneficial in a number of situations where hearing aids are less effective. Because ALDs separate speech from background noise rather than amplify sounds, they can overcome the following obstacles:
- Noisy backgrounds. Competing noise from multiple speakers, busy public venues (such as restaurants and airports), city traffic, ventilation systems and more can interfere with your comprehension.
- Distance. Sound fades with distance. The farther you are from the speaker, the more difficult it is to follow the conversation.
- Poor acoustics. In large, open spaces, sound waves bounce around the room, causing reverberation and distortion.
With hearing aids, turning down the volume to decrease the distracting sounds is your only solution. Unfortunately, when doing so, you are also turning down the volume on the speaker, making that person harder to follow.
ALDs improve the listening experience in these types of situations significantly. They consist of a microphone that is placed near (or on) the speaker instead of being built into the hearing aid, a handheld receiver that picks up transmitted speech and a receiver that broadcasts speech to the listener’s ear (or hearing aids if he/she is wearing them). ALDs use wireless technology and are compatible with a large variety of electronic devices including TVs, cell phones and computers.
There are many different types of ALDs, each with their own unique advantages in certain situations. Popular choices include FM systems, which rely on radio signals to transmit sounds directly to the user; infrared systems, which accomplish the same task using beams of light instead; and hearing loops, which utilize a magnetic loop of wire to send clear sound directly to any hearing aids that include a telecoil option.