A Comparison of Loop, FM and IR Technologies For Assistive Listening

LoopCompBlog-0112There are many options for assistive listening technologies. This blog post provides a comparison between the three technologies used in assistive listening.

There’s been a lot of discussion about loop technology for use in assistive listening. The recent New York Times article “A Hearing Aid That Cuts Out All The Clatter” points to the many benefits of using induction loops in theaters, places of worship and other venues. Thus, the purpose of this blog is to provide a comparison between the three technologies used in assistive listening.

RF (Radio) Technology – This uses the same technology used by a radio station or a two-way radio to wirelessly deliver audio to your ears using an RF receiver and earphones. The system uses a small transmitter with an antenna to cover an entire theater or stadium.

IR (Infrared) Technology – This uses infrared light (yes, the same IR technology as in your TV remote control) to transmit audio to your ears using an IR receiver and earphones. These systems uses IR radiators (it’s like a headlight on a car) to flood IR light into the facility. Most facilities require about four radiators to be installed throughout the venue.

Induction (Loop) Technology – Loop technology uses a magnetic field to wirelessly transmit audio to your ears using either a hearing aid with a built in “T” switch or a loop receiver with earphones. These systems use a wire or loop that is typically installed in the floor of the entire venue. This is the reason that loop systems cost so much more than RF or IR system, especially in retrofit installations.

If you’re like 10 percent of the population and you struggle to hear, assistive listening systems like these can dramatically improve your ability to enjoy the content delivered by the venue. All three of these technologies offer this advantage whether you have a hearing aid or not.

LoopCompBlog2-0112The “Magic” Of Loop Systems

Now, if you do have a hearing aid and it has a “T” switch, a loop system makes it very simple to use. You simply walk into the venue, set your “T” switch and presto you hear audio right in your ears. You don’t need a receiver or earphones. It’s magic! In fact, no one even knows you are hearing the venue audio. This is why loop systems have such a wide appeal for people who have “T” switch hearing aids.

In North America, many people who have hearing aids don’t have a “T” switch where in Europe most hearing aid users do have a “T” switch. My hearing aid does NOT have a “T” switch, and thus, no matter what type of technology a facility might have, I have to get a receiver and earphones to hear the audio. Maybe my next hearing aid will have a “T” switch.

Thus, the “magic” of a loop system can only be enjoyed by those individuals who have a hearing aid with a “T” switch. Everyone else must use a receiver and earphones. The fact is that the majority of people who are hearing impaired do not even own a hearing aid.

Advantages of RF And IR Systems

RF and IR technology assistive listening systems offer two main advantages:

  1. Low cost
  2. Ability to deliver multiple audio sources

The cost of a typical RF system is less than $5,000 and the cost of an IR system is less than $10,000 for an average venue. Loop systems are much more. The lower cost of RF and IR is because of building does not need to be modified to be installed. In loop system systems, the loop must be installed over the entire floor of the venue and it must be carefully designed and installed to ensure complete coverage and no interference to equipment within the facility.

LoopCompBlog3-0112Additionally RF and IR systems can also be used for multiple audio sources. For example, at the Kennedy Center they use their IR system not only for assistive listening but they also use it for audio description and audio instruction.

While the New York Times article “A Hearing Aid That Cuts Out All The Clatter” referenced this facility, the Kennedy Center does not use loop technology* because of their requirement to transmit multiple audio sources.

If a person does have “T” switch hearing aid, they can still use an RF or IR system to connect directly to their hearing aid. This is done by plugging a neck loop into an IR or RF receiver (it’s worn around the neck). The neck loop inductively connects to the hearing aid.

It is great to hear the enthusiasm and the interest in loop system for assistive listening. Loop systems offer a great convenience and “magic” factor people with “T” switch hearing aids. And no matter what technology a venue chooses, anyone can use and benefit from the system.

When you consider 10 percent of the population is hearing impaired (just like me…) it’s important that we have the ability to enjoy a play or enjoy the music.

This chart offers a side by side comparison of some of the considerations for each type of technology:


Consideration RF Technology Infrared Technology Induction Loop Technology
Can be used with a hearing aid that has a “T” switch without ANY other equipment No No Yes
Can be used with a hearing aid that has a “T” switch but requires a neck loop plugged in to an FM or IR receiver Yes Yes Not Applicable
Relative convenience level for individuals with a hearing aid that has a “T” switch Medium Medium Very High
Relative convenience level for individuals with a hearing aid that DON’T have a “T” switch Medium Medium Medium
Relative cost of installation for a new building Low Medium High
Can be used for applications beyond assistive listening such as audio description, language interpretation, etc. Yes Yes No
Maximum number of simultaneous channels 6 32 1
Secure. Signal does not travel outside the room No Yes Yes (if designed properly)
Relative audio quality High High Low
May interfere with equipment within the facility (such as a mixing console) No No Yes

* The NY Times article was reference a one-time event that had a temporary loop system installed.
This was reprinted with permission from Listen Technologies and originally appeared here.