Positioning the shell of a BTE hearing aid behind the ear makes it possible to use larger shells than in-the-ear or receiver-in-canal hearing aids. In turn, this means the hearing aid has space for more hardware than smaller hearing aids, including assistive listening systems such as telecoils, FM systems, and Bluetooth connectivity.

A telecoil is a small coil of wire wrapped around a tiny metal rod in the BTE hearing aid’s shell. Telecoils act as antennas, picking up sound transmitted as magnetic signals sent by “hearing loops” or “audio induction loops.” A hearing loop is an assisted listening system often used by churches, concert halls, universities, airports, museums, and even taxis. Hearing loops can also transmit sound from some televisions and music systems.

Hearing aids with telecoil capabilities have t-switches so you can switch from the hearing aid’s microphone to listen to the hearing loop broadcast. Some BTE hearing aids include a microphone/telecoil setting so you can listen to the telecoil and microphone at once, for situations where you want to follow the telecoil signal and converse at the same time.

An FM signal may be used as an assistive listening system. FM signals work like radios, transmitting at a specific frequency. Hearing aids with FM capabilities can pick up this frequency, transmitting it to your hearing aid speaker. FM signals are common in classrooms, theaters, museums, and some meeting rooms. They may also be used in restaurants and nursing homes. 

Bluetooth connectivity is increasingly common in hearing aids. Bluetooth allows you to listen to televisions, computers, music players, and radios through your hearing aid.

It can sometimes be difficult detecting which direction a sound is coming from when you use a hearing aid. Hearing aids with directional microphones have two or more microphones which pick up sound from different locations, making it easier to tell if sound comes from in front of or behind you. Directional microphones are especially useful for reducing background noise during conversations in restaurants and other noisy environments. 

BTE hearing aids can be used by people of all ages, including children. They are the most versatile of hearing aids, both in terms of extra features and their ability to treat everything from mild to severe hearing loss. Other advantages of BTE hearing aids include:

• Greater amplification than other hearing aid styles
• Easy access to controls for customization and changing settings
• Easier to handle than smaller hearing aids
• Wide range of styles and battery options, including rechargeable features
• Little risk of moisture or earwax damage as the shell sits behind the ear
• Well-suited for individuals with excessive earwax or draining from the ear
• Easy to use

Most BTE hearing aids use size 13 (orange) disposable zine-air batteries which last five to seven days. Power and superpower BTE hearing aids may use size 675 (blue) batteries, which last a similar amount of time. Actual battery life depends on multiple factors, including how long you use your hearing aid each day, volume settings, and whether you use additional features such as Bluetooth or telecoils.

Many BTE hearing aid models now come with built-in rechargeable batteries [NH1] and a charging dock. If your hearing aid is rechargeable, charge it every night to ensure you have sufficient battery power for the next day.