Assymetric hearing loss (one ear good and one ear bad)
Why two ear is the system to strive for!
You would think that if you had one good ear you would do as well hearing and understanding speech as if you had two good ears. But this is not a correct thought and not what the research shows. We have two ears for a reason. Research from professionals in this field have found that children with unilateral hearing loss have as many difficulties as children who have hearing loss in both ears in more difficult listening environments like hearing in noise, with directional speech and with distance speech. These children also do not perform like normal hearing individuals according to Jill Firszt, Ph.D at Washington University said at the Mayo clinic conference (2015).
I have a unilateral hearing loss, my left ear has normal hearing and my right ear has a significant moderately severe loss. While in a quiet environment, talking to someone one-to-one, I do fine without a hearing aid. When listening in any kind of noise or with distant speech I suffer in understanding. Also I have a hard time finding environmental signals and hearing in a spatial world (sounds coming from all around your head). This can be dangerous when crossing streets or even driving. I can’t hear when my blinker is on for example or tell where an emergency vehicle is coming from.
With two ears we can manage the speech information in back ground noise. First with two ears we just can hear louder. Audibility is the first critical point. With two ears then we can use the queues from one ear to another to get rid of the back ground noise. There are timing and intensity issues to help gather information to our brain to process this speech.
Hearing the soft sounds in background noise improves speech understanding. Think of the soft important sounds that are in speech like s, th, b, p and also the differences in hearing a “a” from an “eee”. Hearing soft sounds at a distance helps you also separate out important features in speech which is also critical considering that visual cues at distance are not as available.
Processing this information from both sides of the ear, hence to both sides of the brain are very important to understanding. If a child or an adult doesn’t get both sides of the brain engaged with information, then I often hear people say they didn’t quite understand what was being said and lose the ability to stay on topic in a dynamic conversation. Imagine sitting at a table of 4 or 5 friends or family members and everyone is excited about a conversation. People with hearing loss on one side will do as poorly than people with hearing loss on both sides without aid.
In my years of experience and with my own loss in one ear, I can say that without my hearing aid I feel like I have turned off one ear and have dropped the volume significantly. I have to work harder and I say “what” more. Honestly I don’t and really CAN NOT hear everything because of my loss. Therefore putting on a hearing device seems to make sense.
What is the long term effect? Hearing loss has been related to isolation and loneliness. If you have one good ear and one bad ear and hearing tests have found no difference between hearing loss in both ears and one ear loss then we need to get hearing in both ears for the sake of our overall quality of life!