Are you looking for help with assistive listening devices?
- You work in a facility (school, business, etc) and have been asked to research assistive listening devices and what the law requires you to provide.
- Maybe a family member is showing signs of hearing loss. They turn the TV way up or ask you to “speak up” when you’re talking normally.
Maybe you’ve searched online for hearing assistance devices and been confused by the huge range of options out there.
Or maybe you’ve done some research but need to know about the pros and cons of, say, hearing loop systems versus FM. If this is starting to sound familiar, you’re in the right place…
This page cuts through the technical jargon of assistive listening devices and gives you a quick and easy guide to which system is best for you.
What Are Assistive Listening Systems?
Assistive listening devices (or systems) are tools that help people with hearing loss hear better by amplifying the sound and filtering out noise. This allows individuals with hearing loss to listen at the louder volumes they need, without disturbing others around them. All assistive systems:
- Minimize background noise (improve the signal-to-noise ratio, typically by 15-25 decibels)
- Counteract poor acoustics in a room such as echo
- Reduce the effect of distance between the sound source and ear
How Assistive Listening Systems Work
Whether you’re one person watching TV or designing an audio system for a large auditorium, all ALS systems work essentially the same way. They create an electronic link between the listener and the audio source (for example a movie, presentation, TV show, etc). The sound source is connected to a transmitter which encodes the sounds and sends them to receivers. This way, people can move naturally and not be ‘tied down’ to the audio source.
Systems vary in two ways:
- The type of technology used to transmit the audio signal; and
- The way the signal moves between the listener’s receiver and his/her auditory nerve. Standard headphones are the most common way of doing this. But some hearing aids and cochlear implants can also “tune in” to the audio feed.
Where are Assistive Listening Systems Required?
Many countries require assistive listening systems to be provided in venues where audible communication is critical to using the space. In the United States, these venues include classrooms, courtrooms, public meeting rooms, convention centers, and other public places.
Our compliance guides below will help you determine the exact requirements for your situation:
The Seven Types of Assistive Listening System
1. FM Systems
This is the same technology that powers the radio in your car. With FM systems, the source audio is connected to a transmitter, which sends the signal using FM radio waves to a receiver up to 1,000 feet away. From there, the receivers connect to listeners’ ears via standard 1/8″ headphone jacks. If you have a telecoil equipped hearing aid or cochlear implant, you can use a neckloop to bridge between an FM receiver and hearing aid.
Wi-Fi systems use a digital signal making the audio quality higher than FM systems. One or more Wi-Fi routers broadcast the signal to all devices in range, creating a zone of coverage or “hotspot.” The audio feed can be secured with a password.
3. Infrared (IR)
Infrared systems use an invisible beam of light to send the signal between the transmitter and the receivers. The same technology is used in TV remotes and some other household electronics. Infrared systems can be found in individual homes (sometimes worn around the neck with earphones plugged in) that will connect to the TV as well as in large facilities.
Bluetooth is a short-range digital radio system found in modern smartphones, tablets, and computers. Like Wi-Fi, the devices have to be “paired” so unauthorized devices can be excluded from listening.
5. Hearing Loops
Hearing Loops (AKA Induction Loops / Telecoil Loops,) are commonly used in auditoriums, theatres, and other facilities. They transmit directly to hearing aids via magnetic field. The “loop” refers to a wire that is installed along the perimeter of a room, usually under the floor. When a loop system is active, individuals with hearing aids that have a T-coil setting, can listen to the audio signal directly into their hearing aids by activating the “T” setting. What about people with no hearing aids? They can also tune into the system using a neck loop, which is an antenna that connects to a receiver.
Hearing Loop Basics
Digital assistive listening systems (such as the DigiWave line of products from Williams Sound) operate similar to FM systems. The only difference is that they use a different part of the radio spectrum and encode their transmission using digital data rather than an analogue format.
7. Personal / Home Assistive Listening Devices
Are you looking for a personal amplifier to compensate for hearing loss at home? To help with watching TV or hearing conversations? These are meant to mimic the effects of a hearing aid or cochlear implant, They pick up the sound in the immediate vicinity, reduce background noise, and transmit it to the listener’s ear with a minimum of signal loss. Unlike the other hearing devices discussed above, they combine the input (mic) with the amplifier and output in a single easy-to-use unit.
Personal Device Basics
Questions To Help Choose a System
With so many options, selecting the right equipment can be a bit daunting. We’ve helped
But if you’re more the “do-it-yourself” type, answering these should point you in the right direction:
- How many listeners will your system need to support?
- What are the applicable laws in my area with regard to the physically challenged and the hard of hearing?
- Will you be traveling to other countries while using the equipment?
- Will the installation be done as part of a building renovation? Or in an already-built space?