Why use assistive listening devices?
Why aren’t hearing aids enough?
ADA mandates effective communication
Notes:
To see how an ALD can be helpful, let’s first look at how hearing aids and ALDs interact. A hearing aid system consists of a tiny microphone that picks up sound waves from the air and converts them into electrical signals, an amplifier that increases the strength of the electrical signals, a battery that provides electrical energy to operate the hearing aid, and a tiny loudspeaker called a receiver that converts the amplified signals back into sound waves and directs them into the ear through a specially fitted mold.
Hearing aids are designed to fit the individual’s hearing loss. If the person has a loss in the high frequencies, those frequencies are amplified, and others are left alone. Similarly, if a person has a loss in lower frequencies, those are the ones that are boosted. Unfortunately, most hearing aids do not discriminate between background noise and the sounds you want to hear. Any sounds of the targeted frequencies are amplified. This is why hearing aids do not provide ‘20/20 hearing’. Hearing aids are great for one-on-one interactions where there is little background noise. However, many situations, especially classrooms and group meetings, do not provide this ideal scenario.
An ALD consists of a microphone that takes in the sound, a transmitter that will send sound signals across a distance, a receiver to convert these signals, and some type of coupling device to transmit either the sound to the listener’s ear or the signal to the listener’s hearing aid. ALDs amplify only the sounds coming across the device’s microphone. The voice of the person who is speaking into the mic is the only sound that is amplified for the ALD user, not the other noises in the room (unless they are loud enough for the mic to pick up). The ALD amplifies all the sounds at the same level, much like turning up the volume on the TV.
When you use the two devices together, you have only the targeted sounds AND the targeted frequencies amplified to fit the individual user. This is the incredible benefit of using ALDs.
The ADA specifies effective communication. Hearing aids alone are often not adequate for class lecture or group meeting situations. ALDs are used to improve the listening environment in these situations so that effective communication can take place.