I have hearing aids for both ears, but have better hearing in my left ear. When in situations where it is important to determine direction sounds are coming from, more easily follow multiple conversations, or in places like restaurants..... I don't use the left hearing aid. Doctor tells me it is better to use both for optimal hearing, but I find this just isn't always the case for me when there are certain noise levels. If left hearing was as bad as my right there would be no choice and I'd need to use both, but I've used hearing aids for seven years now and with little change in hearing, I use one aid often.