Home - Assistive Listening Devices

About the ELI: A New Solution for Cell Phones and Hearing Aids

You may have seen advertising or heard about a new device that is designed especially for those who wear hearing aids but wish to use a digital cell phone. Developed by Starkey, the ELI uses Bluetooth technology to send an audio signal between a digital cell phone and a small module which attached to the direct audio input (DAI) boot of a BTE hearing aid.

Bluetooth is a short-range, wireless digital communication standard. Bluetooth-equipped devices can convey audio or data from one device to another via a secure digital link. Many electronic devices, including digital cell phones, computers, PDAs or handhelds, printers, fax machines and audio equipment are available with Bluetooth.

ELI is one of the smallest Bluetooth devices available, measuring 1.06 x .63 x .43 inches and weighing .18 oz. It has a standard 3-pin connector to attach to the DAI boot on a BTE hearing aid. It can be used with hearing aids without a DAI by using the neckloop in conjunction with the telecoil in a hearing aid. A microphone on the end of the ELI module picks up the wearer's voice and sends it back to the mobile phone.

When the ELI is in use, an incoming call rings through it and is heard through the hearing aid. You answer the call by pressing the device's master control button. The same button is used to hang up calls, as well as to turn the ELI on and off. When the hearing aid receives a signal from the ELI, it suppresses the hearing aid's incoming microphone signal, so the phone is all you hear through the hearing aid. When the call is finished, the ELI disengages and the hearing aid automatically returns to the microphone setting.

Because the ELI uses your own hearing aid to process the audio signal, all the benefits of hearing sound through your hearing aids are available through your cell phone. Here are some other benefits that the ELI offers:

You won't experience unpleasant acoustic feedback, because the phone need not be close to the hearing aid.

Volume is controlled by your hearing aid and the volume control on your cell phone.

Bluetooth eliminates electromagnetic noise via a technique called frequency hopping, in which the carrier frequency randomly changes 1600 times per second across a defined spectral band, eliminating most sources of audible interference.

Bluetooth signals will pass through walls without much degradation, but it has more difficulty with the human body. The position of your cell phone relative to the ELI module is a factor with some phones, and seems to depend on the antenna design of the phone you use.

Switching between cell phone and microphone input takes place automatically if the ELI is attached directly to the DAI boot on your hearing aid. When a call is received, the signal from the ELI suppresses the microphone signal. When the call ends, your microphone is automatically switched back on. If you are using the ELI with a neckloop, your phone will ring as usual, and you will need to manually switch your hearing aid to the telecoil setting for the duration of the call, and back again when the call is complete.

ELI was designed specifically to give hard-of-hearing people access to the convenience of cell phone technology. The buzz and feedback associated with using a hearing aid directly with a mobile phone is gone.

You must use the ELI with a Bluetooth equipped device. Many phones are now equipped with Bluetooth, or you can easily attach a Bluetooth adapter or transmitter to a non-Bluetooth phone. You can also use the ELI with other Bluetooth-equipped devices, such as televisions, radios and MP3 players. A Bluetooth adapter can be attached to any audio device in order to send a signal to ELI, and thus use it as more of a traditional assistive device.

Information has been obtained from "Phones and hearing aids: Issues, resolutions and a new approach"; The Hearing Journal; October 2005, Vol 58, No 10.