I started out with the Phonak Bi-Cros and it worked well for a couple of years. It really did add additional sound I would not have otherwise heard. I could really tell the difference because I would put my hearing aid with the bi-cros "shoe" in on my left (hearing) side first, then add the cros part behind the deaf ear; almost like the difference between mono and stereo. My only complaint with it was that I'm in the computer field and computers make a lot of high-frequency sounds that a regular person doesn't hear, but the RF frequency of the bi-cros picks up. I could also hear the inteference for a second or two when I walked through the security bars at the entrance of stores. I got curious about the BAHA, though, and found that my Aetna insurance would actually pay for it because I lost my hearing due to a tumor and it was considered a type of "prosthetic" device that's replacing the inner ear that was removed during the tumor surgery. The extra sound I get now from it isn't quite as loud as the Bi-Cros I had, but I'm happy not to have the interference anymore, plus the hearing aid on the left side is a lot lighter without the "shoe" receiver snapped on to the bottom of it.