Auditory System Hearing Testing Impairments Amplification Devices

Hearing loss can affect your ability to understand conversations, or to take in information about your surroundings through sound. Individuals with hearing loss often choose to use hearing devices to improve their ability to take in speech and other environmental sounds. These amplification devices can be tailored to you and your specific hearing needs.

Hearing Aids

Hearing aids are popular amplification devices for individuals with hearing loss. Hearing aids receive sound from the environment, amplify it, and project it directly into the ear. Hearing aids are specifically programmed, amplifying only the impaired frequencies for each individual. Several types of hearing aids are available:

  • Behind-the-ear hearing aids consist of a casing containing the electronic components, which sits behind the ear, suspended from a hook that goes over the ear. Tubing travels from the casing to an earpiece that sits in the external ear canal, which funnels amplified sound directly into the ear.
  • In-the-ear hearing aids sit in the ear canal, and are custom-molded to each individual’s ear. All the components of the device are housed within this specially-molded piece. In-the-ear hearing aids can be large, filling the external ear canal, or smaller and less noticeable, fitting completely in the ear canal.

Types of Hearing Aids - Hearing Aids

Hearing aids vary in size and in features. Smaller hearing aids are usually more expensive, and are often only appropriate for mild to moderate hearing losses. More severe hearing losses may require a larger or more powerful hearing aid. Some hearing aids have volume control; others have only an on/off switch. Some hearing aids have a T-coil function, allowing the hearing aid to function with telephone use (without feedback), or to pick up signals from a closed-loop system. Choice of hearing aids depends on several factors, including:

  • Age
  • Budget
  • Degree of hearing loss
  • Lifestyle
  • Manual dexterity
  • Type of hearing loss.

Small batteries often supply the power for hearing aids. Hearing aid batteries can lose charge quickly, so you may want to keep extra batteries on hand. If you wear a hearing aid and it doesn’t seem to be working, check the battery (or have your audiologist or speech therapist check it).

FM Systems

FM hearing systems can be used instead of, or in addition to, hearing aids to amplify sounds for people with hearing loss. An FM system consists of two components: a microphone, worn by the speaker, and a receiver/speaker, worn by the listener. Signal is transmitted from the microphone to the receiver using an FM frequency. FM systems work to increase the signal-to-noise ratio by increasing the volume and salience of the voice of the person wearing the microphone. This decreases interference of background noise.


Heard of Hearing Advocates (n.d.). Telecoils in hearing aids in the USA. Retrieved February 1, 2010, from Hard of Hearing Advocates Web site: