I often get asked by a patient “Can I get away with one hearing aid?” I am often amused by this, because I know that they would never consider getting a monocle if they had vision loss in both eyes. We are born with two ears, and our brains process speech better with input from both ears.
There are several advantages to bilaterally symmetrical hearing. We localize sounds better with proper input from both ears. For example, when a sound comes from the right side, the right ear receives the signal a fraction of a second before the left ear. This tells the brain where the sound is coming from. Our ability to localize sound also improves speech recognition in the presence of noise.
Everything we do has a cognitive load, in other words, it takes energy from the brain. Processing speech is no exception. When the brain processes speech from both ears, it reduces the cognitive load. Basically, it helps the brain process speech easier, especially when there is noise present.
There is a well-documented “summation effect” in the brain. Essentially, the brain takes the signal from each ear individually, and puts them together in the brain, allowing the binaural interpretation to be stronger than the individual input. In other words, when working together, both ears together will require less amplification than individually.
With 2 hearing aids, your improved range of hearing is 360 ⁰, versus 180 ⁰ with one hearing aid. You are able to hear people on both sides of you. You feel more balanced with symmetrical hearing. Additionally, for those who suffer from tinnitus, binaural input is very important. With amplified input on both ears, tinnitus is often masked, making it less bothersome and annoying.
We’ve all hear the adage “use it or lose it.” This is true with hearing. Stimulating both sides of the brain with proper auditory input helps to keep your ability to discriminate speech sharp! The bottom line is that we were born with two ears for a reason. That is how we are made to operate. As the old song says, one is the loneliest number.