Siemens e2e wireless communication for hearing aids - Page 1
Forum section: electronics / general

author: jonmarx
author_rank: Contributor
timestamp: May 11, 2014, 05:03:45 pm
content: Unfortunately I recently had to start using hearing aids, and was interested to discover that my Siemens aids have a short-range wireless communication system called "e2e" that allows the two aids to coordinate their operation. The wireless feature also (if you buy the optional extra kit) allows the aids to be controlled using a remote control and to have music etc. streamed straight into them.It seems an ideal feature to tinker with and try to hack, but there isn't much technical info on the wireless protocol. All I've found is a brief mention in a technical paper:e2e wireless technology uses electromagnetic transmission to communicate between the two hearing instruments, and also between hearing instruments and an optional ePocket™ remote control accessory. The communication is conducted through modulation via frequency shift keying technology, employing transmission frequency shifts between 115 and 120 kHz. Transmission between instruments is enabled for distances up to 30 cm.Does anyone know any more about this e2e system?

author: ConKbot
author_rank: Super Contributor
timestamp: May 13, 2014, 12:04:06 pm
content: Havent read on that, but I have always told my coworker which has a cochlear implant (and corresponding mic/amp on the ear and magnetic transmitter that goes on the back of the head ) that someone should make a bluetooth enabled one. A separate snap-on module so that its not using the batteries of the earpiece, so he could listen to music, or perhaps use the phone. With the implant he could hear enough converse if you spoke clearly, and casual conversation if he could read lips too. He said he liked to listen to music in the car too. But he couldnt use phones or radios. I'm presuming because the lack of clarity.An implant which directly stimulates nerves, combined with some electronics integration always seemed like some very interesting Deus Ex type of tech. (Though perhaps a touch unnerving giving the themes/situations presented in Deus Ex)The good news is that 115-120khz FM should be easy enough to tinker around on, as even a scope 20 MHz of bandwidth can display the signal directly, and be easy enough to poke around with a SDR on that frequency. Or even downmix it with 110 KHz, filter it, and you have something you can put into a sound card to analyze what they are doing.

author: jonmarx
author_rank: Contributor
timestamp: May 13, 2014, 05:22:58 pm
content: You can get hearing aids that support Bluetooth streaming, although due to size and power consumption the Bluetooth circuitry isn't built directly into the aids. Instead you have to buy a separate Bluetooth-enabled box that you carry to convert the Bluetooth audio into a short-range e2e transmission to the aids, e.g. theSiemens miniTek.I've found a bit more information. The e2e system uses near-field magnetic induction (NFMI) to minimise power consumption. ON Semiconductor even produces acustom hearing aid DSPwhich supports NFMI communication, although the data sheet doesn't say anything about the protocol.I managed to pick up the transmissions from my aids using a coil on my oscilloscope; they send a couple of short bursts of data every 5 seconds. However, despite the information I posted earlier, it looks like in my case the carrier frequency is around 3MHz.