A Answers (1)
David Vernick, Otolaryngology, answeredThe reason two hearing aids are often better than one is that they take advantage of the way the brain processes sound signals. With normal hearing, sound signals from both ears are comparable in strength. The brain can pick out the important signals, like voices, when they're louder than the background noise. But if you're wearing just one hearing aid and someone talks into your unaided ear in a noisy room, the voice may sound softer than the background noise. As a result, it's harder for your brain to give it preferential status. It may also be harder for the brain to identify the location of particular sounds. The brain normally does this by comparing the qualities of the sound signals that come through each ear -- their relative loudness, frequencies, and the time it takes them to travel through the ears. But the brain can't locate a sound as well if sound signals are always louder through one ear.