Live and Recorded Media:
Assistive Listening Devices
What Assistive Listening Devices Are and Who Uses Them
Assistive listening devices (ALDs) allow people who are hard of hearing to participate more fully in museum programs and activities. They do this by increasing the volume of a desired sound, such as the soundtrack of a movie or the voice of a tour guide, without increasing the loudness of background noises. Some assistive listening devices are also used to convey audio descriptions to visitors with visual impairments. Museums use ALDs in live performances, films, planetarium shows, lectures, large format theaters, and guided tours.
It is estimated that one out of every 10 people in the U.S. has a significant hearing loss, ranging from 25 dB (mild) to 90 dB (severe). About half of them are older adults. Among people with hearing loss, some wear hearing aids or use other devices to enhance what hearing they have, and some read lips.
Whatever auxiliary aids and services you provide to visitors, be sure to advertise their availability in brochures and on your web pages. Also, be sure to use appropriate signage and symbols in the museum to alert potential users to where they can request an ALD.
Museums cannot charge visitors for use of ALDs. If options are available, staff should always ask visitors which device they need or prefer.
Also, staff who dispense ALDs need to be trained in their use and maintenance. Maintenance may include routine equipment checks and recharging batteries.
Before reading descriptions of various ALD systems, it may be helpful to know that ALDs are made up of two parts: the transmitter and the receiver. The transmitter picks up the sound and converts it to a signal, which it then sends out. The receiver picks up a signal and transmits it to the visitor. Several receivers can pick up the signal from a single transmitter.
Infrared systems transmit sounds via light waves to users wearing receivers. The receiver must be in the transmitter's line of sight to function properly. This limits where visitors with receivers can be located, but it also prevents spillover of sound into other areas. Sunlight and bright incandescent light interfere with the transmitter signal, so an IR system may not be a good choice for outdoors. IR systems are often used in movies, conferences, and live performances.
FM systems transmit sounds via radio waves. With this system, the speaker wears a compact microphone and transmitter while the listener has a portable receiver with headphones or earphones. FM systems are commonly used when the speaker is required to move around. This system is not affected by light, but may experience radio interference. The same system can serve multiple uses (e.g. translations, audio descriptions, etc.) because it can transmit and receive multiple frequencies.
Inductive or audio loop systems transmit sounds using an electromagnetic field. A special amplifier and microphone used by the speaker send signals through a loop of wire installed around the listening area. Hearing aids equipped with telecoil circuits receive these signals and transmit them as sound to the visitors. You can provide visitors who do not have hearing aids or telecoil circuits with receivers that pick up the signal.
The equipment you need will varies according to how you plan to use ALDs. You will need at least a transmitter and several receivers. The Americans with Disabilities Act Accessibility Guidelines specify the number or percentage of receivers required in various situations. Research your options thoroughly before selecting the device that will work best for your situation.
Many resources on audio description recommend purchasing receivers with multiple channels so that a single receiver can be used for assistive listening, audio description, or translation into other languages. A multi-channel system also should allow stage sound and audio description to be heard simultaneously.
Where to Get the Equipment You Need
Informed Consumer Guide to Assistive Technology for People with Hearing Disabilities
This document produced by ABLEDATA provides information on many kinds of assistive devices for people with hearing loss. It concludes with a list of manufacturers of assistive devices for people who are deaf or hard of hearing. The ABLEDATA site also contains consumer guides, fact sheets, bulletins, and directories that are very thorough.
ASHA Buyer's Guide for Communication Devices/Aids, Audiology
The American Speech-Language-Hearing Association (ASHA) has compiled this list of companies that manufacture and/or distribute assistive listening devices. The directory is not as easy to use as the ABLEDATA guide and occasionally has incomplete information on the companies.
Links Related to Assistive Listening Devices
American Speech-Language-Hearing Association (ASHA)
On ASHA's web site you will find information about hearing loss, its effects, and assistive technologies. In the public information section there are links to several brochures about ALDs and other topics you might find useful.
Deaf Linx is designed to be a one-stop shop for legal deaf cultural resources, American Sign Language (ASL) resources, deaf education, and deaf services. There are many resources on this site to help you find more information on the deaf community and gain a better understanding of ASL.
Directory of State Technology Assistance Programs
Under the Technology-Related Assistance for Individuals With Disabilities Act of 1988, each state has an organization that provides information on assistive technologies. These organizations can provide technical assistance to help you decide what technologies would work best in your museum. They sometimes sponsor demonstrations of various technologies or organize special events. These programs work with all kinds of assistive technologies, not just those for people who are deaf or hard of hearing.
Self Help for Hard of Hearing People (SHHH)
As part of SHHH's goal to improve the quality of life for people who are hard of hearing, it provides information and services regarding hearing loss. This web page describes various kinds of ALDs. SHHH also allows consumers to try out hearing assistive technology before they purchase it.
This web site is not intended to offer legal, architectural, engineering, or similar professional advice. Refer specific questions to an attorney or an ADA authority.