Department of Speech and Hearing Science

What are Assistive Listening Devices

Assistive devices include any device, except hearing aids, which help a deaf or hard of hearing person communicate more effectively through direct sound amplification or visual or vibrotactile alerts. Assistive devices include an array of technology: Television and telephone aids, alerting or signaling devices, and personal or large area assistive listening systems. Assistive devices are also known as auxiliary aids, assistive listening devices or ALDs.

At the ASU Speech & Hearing Clinic we are dedicated to full communication accessibility for all persons with hearing loss. As professional audiologists, we view assistive devices as a vital link in the larger framework of maximizing the communication skills for hard of hearing and deaf persons in all aspects of their daily lives. For many individuals, the use of hearing aids or alternative methods of communication will enhance their communication and listening skills. However, these methods alone cannot be expected to solve all difficulties that result from hearing loss or deafness. It is important for individuals to become aware of the many other resources available that can ease functioning in everyday life.

Who Can Use Assistive Devices?

Assistive devices can improve communication and understanding for individuals with varying degrees of hearing loss. For persons with a very mild hearing loss who may not yet want a hearing aid, assistive devices can meet a specific listening need such as improved communication over the telephone or greater ease while watching TV. For persons with greater degrees of hearing loss, assistive devices can supplement personal hearing aids by providing clearer communication in some environments and by alerting them to sounds and situations that may not be heard under adverse conditions or when the hearing aids are removed. For persons with a profound or total loss of hearing, assistive devices can provide a visual or vibrotactile medium for greater telecommunication accessibility, enjoyment of television, or the detection and identification of environmental sounds.

Businesses and employers use assistive devices to provide increased accessibility and "reasonable accommodation" for patrons or employees with hearing loss. Assistive devices are a vital link in complying with the Americans with Disabilities Act (ADA) and in achieving effective "communication accessibility".

Why Use Assistive Devices?

A hearing loss, of any degree, can create a barrier to effective communication. Communication is how we interact with others and the world around us. We use our hearing for interpersonal and group communication, for communication over the telephone, for the reception of TV or music, and for the awareness of sounds in our environment such as a door knock, a smoke alarm, or a baby crying. An inability or difficulty in communicating in any of these areas leads to a "communication disability".

Assistive devices provide "communication accessibility" by helping to break down the barriers to effective communication.

Assistive devices can help to make interpersonal and group communication more manageable in noisy environments, in situations with poor acoustics or where distance is a factor. Assistive devices can provide an enhanced auditory signal for better reception of telecommunication and media signals. They can substitute visual communication for auditory when necessary and can monitor important sounds in the environment through vision or tactile sensation.

Personal assistive listening devices (ALDs) provide communication accessibility even under these adverse listening conditions by increasing the loudness of specific sounds only. Personal ALDs all use the principle of a remote microphone that is placed as close to the sound source as possible or a direct plug-in connection to an audio source (i.e. TV/stereo, telephone, etc). In this way, the desired sound is sent more directly to the ear of the listener making it possible to hear regardless of environmental conditions. Personal ALDs may be used by people with all degrees of hearing loss whether or not they also use a personal hearing aid. When used with the personal hearing aid, ALDs extend the "reach" of the hearing aid permitting the user to function more effectively in situations that previously were difficult or impossible. These devices use either hardwired or wireless transmission. Each technology has specific features, capabilities, advantages and disadvantages that should be considered when selecting an appropriate assistive listening device for a specific application.

Hardwired Assistive Listening Devices

Hardwired ALDs use an actual cord or wire to transmit the sound, thereby tethering the listener to the sound source. A hardwired ALD is typically lower in cost, easy to use, and is very portable. It is excellent for situations where the listener-to-speaker distance is not too great, such as in an automobile, restaurant or for TV viewing. It is also excellent as a temporary form of amplification such as may be needed in a doctor's office, hospital or nursing home. A disadvantage of the device is restricted mobility and limited seating arrangements which are dictated by the length of the cord. This limits the usefulness of a hardwired ALD in larger communication situations such as in a classroom, meeting or tour group.

Wireless Assistive Listening Devices

Wireless ALDs send the signal without the direct physical connection of a cord between the sound source and the listener. Wireless systems consists of a transmitter placed close to or directly connected to the sound source and a wireless receiver worn by the listener. The wireless transmission between transmitter and receiver can be either FM radio waves, invisible infrared light or electromagnetic energy. Wireless technologies can be more portable depending on signal strength and device range and can be limited by security of signal and line of sight.

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