Skip Navigation - Site Features
A man playing a saxophone on stage. Painting of a hand cupped around a tiny infant. Vibrantly colored painting of geometric renderings of faces. A woman sculpting a bust out of clay. Close-up of a painting of a human eye in shades of black, red and orange. A woman performing in a play on stage. A young boy smiling at a hand puppet. An exuberant group of participants in the Actual Lives program. A young boy participating in the Arts Alive program. Painting with white and blue hair-like strokes on a background of deep turquoise. Man in a wheelchair viewing artwork in a gallery. Blind artist standing in front of his work. Group of women performing with colored scarves. Man speaking into a microphone with open captioning on a large screen behind him. Group of young students playing a musical game with the teacher.

ADA Toolkit - Assistive Listening Systems for People who are Hard of Hearing

Assistive Listening Systems (ALS) and/or Assistive Listening Devices (ALD) are any technology developed to enhance the abilities of a person who is hard of hearing, to better hear and understand public presentations. These systems can be used with a television set, in small gatherings, in class or meeting rooms, and in venues like auditoriums and theatres.

What do they do?

ALS's and ALD's amplify sound. Because these systems and devices frequently tap directly into the source of the sound by using a microphone clipped to the speaker or suspended above a stage, they help to clarify sound by cutting down or eliminating ambient noise. But, primarily the job of the ALS or ALD is to make the source sound louder and give volume control to the individual.

Who uses Assistive Listening Systems?

America has an estimated 32.5 million adults who are deaf or hard of hearing. Of these, 19 million have some residual hearing that enables them to benefit from the use of assistive listening systems. 15 million people who can benefit from the use of an ALS do not use hearing aids and 4 million use hearing aids. *Source: Summary Health Statistics for U.S. Adults, National Health Interview Survey, 2003, tables 11, 12, 18 and 19.

How do Assistive Listening Systems Work?

There are two primary modes of transmitting sound: via radio waves and via infrared waves. There are basically four types of systems which all include a microphone, transmitter, receiver and headset. The mixer/amplifier and transmitter are frequently one unit.

The hardwire system is a closed system, meaning the sound is never broadcast outside of the cables. This is the type of system used in airplanes where the headset is plugged directly into the jack at your seat.

The induction loop system broadcasts via radio waves within an area encompassed by a big directional antenna. To get amplification the individual must be seated within the area the antenna circles.

The FM system operates just like a small radio station with pre-set frequencies, that the FCC has determined and restricted for use by assistive listening systems.

The infrared system is known as a "line of sight" system since the receiver must be in line of sight of the emitter because infrared waves will not go through a solid object.

Four Basic Systems: infrared, FM, loop, hardwire

Types of Headsets: over the head, under the neck, monaural, binaural, induction loop

Types of Receivers: two types of receivers


Visit the Kennedy Center's Accessibility Resource for more information on Assistive Listening Devices.


Directory of Manufacturers and Vendors

The following is a list of manufacturers and/or suppliers who carry assistive listening systems that are used in facilities and venues like classrooms or theaters. This is not a comprehensive list nor does inclusion on this list imply any kind of an endorsement of the company or product.

Call the manufacturer or supplier and find a vendor in your area who can sell, install, and help you maintain your equipment. Some manufacturers will sell directly to the public and some will not. (M=Manufacturer, S=Supplier)

All Systems

Audio Enhancement (S)
14241 South Redwood Road
P.O.Box 2000
Bluffdale, UT 84065
(800) 383-9362
(801) 254-9263
(801) 254-3802 Fax

Cardinal Sound & Communication (S)
2317 Kansas Avenue
Silver Spring, MD 20910
(800) 964-3496
(301) 589-3700
(301) 589-4284 Fax
www.cardinalsound.us/main

Centrum Sound (S)
572 LaConner Drive
Sunnyvale, CA 94078
(408) 736-6500
(408) 736-6552 Fax

Clearone Communications Corporation (M)
1825 West Research Way
Salt Lake City, UT 84119
(800) 975-7200
(801) 975-7200
(801) 977-0087 Fax
www.clearone.com

HARC Mercantile, Ltd. (S)
1111 West Centre Avenue
Portage, MI 49024
(800) 445-9968 Voice
(269) 324-1615 TTY
(269) 324-2387 Fax
www.accessolutions.com

HITEC (S)
8160 Madison Avenue
Burr Ridge, IL 60521
(800) 288-8303 voice
(800) 536-8890 TTY
www.hitec.com/hitec

Phonic Ear, Inc. (M)
3880 Cypress Drive
Petaluma, CA 94954-7600
(707) 769-1110
(800) 227-0735
(707) 769-9624 Fax
www.phonicear.com

Potomac Technology (S)
1 Church Street, Suite #101
Rockville, MD 20850-4158
(800) 433-2838 Voice/TTY
(301) 762-1892
www.potomactech.com

FM and Infrared Systems Only
Listen Technologies Corporation (M)
14912 Heritage Crest Way
Salt Lake City, UT 84065-4818
(800) 330-0891 Toll Free
(801) 233-8992
(801) 233-8995 Fax
www.listentech.com

NADY Systems Inc. (M)
6701 Shellmond Street
Emeryville CA 94608
(510) 652-2411
(510) 652-5075 Fax
www.nadywireless.com

Sennheiser Electronic Corp. (M)
1 Enterprise Drive
Old Lyme, CT 06371
(860) 434-9190 Voice
(860) 434- 1759 Fax
www.sennheiserusa.com

Williams Sound (M)
10399 West 70th Street
Eden Prairie, MN 55344
(612) 943-2252
(800) 328-6190
(612) 943-2174 Fax
www.williamssound.com

Infrared Systems Only

ALDS, Distributing Inc. (M)
20540 Duncan Way, Unit #103
Langley, B.C., Canada V3A-7A3
(604) 514-0053 Voice
(866) 845-ALDS
(604) 514-0037 Fax
www.alds.com

Audex (M)
710 Standard Street
Longview, TX 75604
(903) 295-8244
(800) 237-0716
(800) Audex-74 Fax
www.audex.com

Lightspeed Technologies
11509 SW Herman Road
Tualatin, OR 97062
(800) 732-8999
(503) 684-3197 Fax
www.lightspeed-tek.com

Siemens Hearing Instruments (M)
P.O. Box 1397
10 Constitution Avenue
Piscataway, NJ 08855
(732) 562-6600
(732) 562-6696 Fax
www.siemens-hearing.com

Ultra*Stereo Labs, Inc. (M)
181 Bonetti Drive
San Luis Obispo, CA 93401
(805) 549-0161
(805) 549-0163 Fax
www.uslinc.com

FM Systems
Telex (M)
12000 Portland Avenue, South
Burnsville, MN 55337
(952) 884-4051
(952) 884-0043 Fax
www.telex.com

Induction Loop

Systems
AssistiveAudio (S)
2627 Algonquin Parkway
Toledo, OH 43606
(800) 224-9295 Voice
(419) 292-2169 Fax
www.assistiveaudio.com

Oval Window Audio (M)
33 Wildflower Court
Nederland, CO 80466
(303) 447-3607 Voice/TTY/Fax
www.ovalwindowaudio.com

VSA Texas is always looking for people to join us in our goal of assisting arts organizations to achieve maximum accessibility.

Contact VSA Texas for more information on how you can help.

Copyright © 2007 VSA Texas, All Rights Reserved. Legal Statements