The majority of hearing aids today use zinc-air batteries. This kind of battery is made specifically for hearing aids and comes in a variety of sizes to work with different devices. You can find hearing aid batteries at almost any store that sells regular batteries, including most pharmacies and grocery stores.

This depends on the type of battery and how many hours per day you wear your hearing aid. Smaller hearing aid batteries need replacing within one week, while larger batteries may last two to three weeks.

Here’s why two hearing aids can be better than one:

Better hearing in a noisy environment: Hearing in a noisy environment can be improved if the signal reaching each ear arrives at a slightly different moment in time. This time difference can help the brain process a speech signal more efficiently.

Improved signal vs. noise level: Sound source matters: If you have a hearing aid in only your left ear and the person speaking to you is on your right side, much of the speech signal is lost by the time it gets to your aided ear, while the level of the noise in the room enters the aided ear at its normal volume level.

Improved ability to localize sounds: The brain uses the sound entering the ears from the right and left side of the head to determine the direction of the sound source. Having a hearing aid in only one ear can alter this sense of direction.