Cell Phone Amplification Provided Through: Hearing Aid Compatibility (HAC) and Hearing Assistive Technology (HAT)

Cell phone amplification allows persons with hearing loss to be able to communicate more clearly with less noise or static distortion. In order to get the most bang for your buck, when looking into obtaining a phone and/or special equipment for this enhancement it helps to have a basic understanding of both hearing aid compatibility (HAC) and hearing assistive technology (HAT). This blog will look at a basic overview of both with a more elaborated explanation on Bluetooth and Telecoils following.

Hearing Aid Compatibility (HAC)

According to the Federal Communications Commission (FCC), the Hearing Aid Compatibility Act and other federal laws ensure the availability of wireless telephones that are compatible with hearing aids and cochlear implants.  Wireless telephones that are certified as being hearing aid compatible should minimize unwanted noise and be compatible with the magnetic coils (telecoils or T-coils) in many hearing aids.

Healthy Hearing states that when shopping for a phone, look for what’s known as the M rating for hearing aid compatibility. The M rating ranges from 1 to 4, with 4 being the best compatibility. A higher rating means less distracting noise and feedback coming in, but some unwanted noise is still possible. M3 is perhaps the most common rating. Further, your telecoil may automatically switch on or it may require you to manually switch into the telecoil or “T” mode. Ask your hearing healthcare provider for more details. This is something you’ll want to test out when trying out different phones. If you plan to use the telecoil feature, look for what’s known as the T rating for hearing aid compatibility. The T rating also ranges from 1 to 4, with 4 being the best. Many cell phones today are T4.

Hearing Assistive Technology (HAT)

Hearing Assistive Technology (HAT) can dramatically improve the lives of people with hearing loss. Assistive listening systems and devices bridge the gap between you and the sound source by eliminating the effects of distance, background noise, and reverberation. They can bypass challenging acoustics—sending sound directly to users’ ears. The Hearing Loss Association of America (HLAA) is a great place to learn all about HATs and other things related to hearing loss.

Hearing aids with a telecoil can make a dramatic difference in the user’s ability to hear clearly on the telephone, in meetings, a noisy restaurant, at the theater, and while navigating buses, airports, train stations and other challenging environments.

All assistive listening systems are required to be accessible for people with hearing aids, people with hearing aids but no telecoil, and people without hearing aids.

There are three types of assistive listening systems that provide ADA mandated communication access in public places. First are hearing Loops, also known as Induction Loops or Audio Frequency Induction Loop Systems (AFILS), consist of a copper wire placed within a room, theater, or counter which is connected via a special loop “driver” to a public address or sound system. An electromagnetic field is created that connects to a telecoil in hearing aids, cochlear implants, or telecoil receivers. Loops are the most user-friendly of assistive listening options. Next, Infrared Systems (IR) work like TV remote controls. A transmitter sends speech or music from a public address or sound system to an IR receiver using invisible infrared light waves. This technology is line-of-sight and cannot be used outdoors during the daytime due to being affected by light. Thirdly, FM Systems, or Radio Frequency Assistive Listening Systems, transmit wireless, low power FM frequency radio transmission from a sound system to FM receivers. An advantage of this system over an infrared system: FM is not affected by direct sunlight.

Confused? HLAA has created a new service called HAT HELP which is staffed by volunteers. Supervised doctoral level audiology students from the University of Washington and Gallaudet University are now available to answer your technical assistance questions. Simply write to hat_help@hearingloss.org and they will provide an email response.


Healthy Hearing states that Bluetooth technology is the latest innovation to take off among hearing aid users. Although Bluetooth hearing aids are not yet available, the technology allows two devices such as a cell phone or computer, for example, and a wireless hearing aid with a compatible streamer to talk to each other. The range is limited, somewhere around 20 feet, but the lack of interference and secure connection of this convenient hands-free technology outweighs any negatives. In addition, the use of one streamer can allow the user to switch back and forth among multiple devices, from cell phones to tablets to iPods.

Another page on their website dedicated to this topic further elaborates that Bluetooth is a wireless communication platform that allows for the transfer of data between two or more electronic devices. The technology uses radio waves set to a high frequency to transmit data without interference or security risks. If your hearing aid doesn’t include a feature for direct streaming from your smartphone to your hearing aids, don’t worry. Manufacturers of wireless hearing aids long ago created a clever solution for accessing this prevalent wireless standard. Wireless hearing aids can use compatible assistive listening devices, often called streamers, to provide a communication link between the wireless technology in the hearing aids and any Bluetooth-enabled device.

This type of technology allows users more options and opportunities including personalized listening experience, multiple connections, remote control of your hearing aids, and standard protocol (which means there is uniformity in the way that it works across all devices).


Based on just the above information it is apparent that telecoils (also called t-coils) are important and can enhance the usability of hearing assistive devices but what are they?

Everyday Hearing provides an excellent article concerning this very thing. The following are highlights from this article. A telecoil is a small copper wire coil located within some hearing aids and cochlear implants. It is designed to communicate with telephones and loop systems through an electromagnetic wireless signal. The goal of a telecoil is to enhance and “clean up” the speech signal coming through the audio system, whether it be a telephone or a microphone, such as in an auditorium or place or worship. Because it’s a direct wireless transmission, the telecoil signal volume can be adjusted by the listener.

Not all hearing devices have telecoils. The smaller the device is, the less likely it will contain a telecoil. This is because the telecoil takes up too much space for them to fit within the smallest devices, such as a completely in the canal (CIC) or micro behind the ear (BTE) hearing device. Most cochlear implants have telecoils built within them. In general, any hearing device equipped with a size 10 battery will not include a telecoil.

The worse your hearing is, the more difficulty you will have hearing on the telephone or in large rooms and public places. For this reason, a telecoil will become very useful for improving speech understanding in these situations.

Cell phone amplification devices currently highlighted for the week include the Bluetooth T-Coil Headset for Cell Phones, Blue Tooth Cell Phone Amplifier for Behind The Ear Hearing Aids, and HearAll Cellphone Amplifier.

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