“Why can’t I just get one hearing aid?” is a common question in any audiology practice. Years and years ago, even with hearing loss in both ears, it was common practice that one hearing aid would be “good enough.” Yes, there are folks today who use just one hearing aid, and there are different reasons why this might be the case, but generally when someone has hearing loss in both ears, the best practice is to amplify both ears. The following are some reasons why someone might have one hearing aid:
Some people have hearing loss in one ear and normal hearing in the other. If the ear with hearing loss is useable, which is measured by the degree of word recognition at a loud enough volume to compensate for the decreased hearing, then amplifying the hearing-impaired ear can make a lot of sense. It can equal out the information provided to the brain from the other ear, provide localization, and help with hearing in difficult listening situations.
If hearing loss in one ear is not useable, which is determined by measuring a poor degree of word recognition in the hearing-impaired ear, then a hearing aid may not be recommended. People with non-useable hearing loss may choose to do nothing and try to compensate with one ear only. This is a case where someone has a hearing loss — which may not be noticeable to anyone else — but they struggle tremendously in a noisy environment because of poor localizing ability.
Hearing loss can also be significantly different between each ear. Someone may have useable mild to moderate hearing loss on one side and non-usable hearing on the other. This could be due to a number of factors, from injury to infections. This person has hearing loss in both ears, but may only use a hearing aid on one side because the brain only processes sound successfully on one side. Although a hearing aid is necessary for this person to be involved in any conversation — and they will seem to hear well in quiet — they will still struggle greatly in a noisy place due to the use of only one ear.
Even with non-usable hearing on one side, many individuals benefit from a CROS or contralateral-routing-of-signal type of hearing aid. This kind of hearing aid is actually two small devices — one worn on each ear. A transmitter on the unusable ear sends sound from that side to a receiver on the good ear. This allows the user to hear voices from their “bad” side, and this is an example of someone who has hearing loss on only one side but will appear to be wearing two hearing aids. This type of hearing aid may help balance out sound. They may not be able to figure out where you are when you are calling them from behind, but they will hear a voice from their “bad side” and have help when trying to understand conversation in a noisy place.
Research has proven time and again that hearing is a complex process. The complexities of hearing loss also illustrate the importance of a comprehensive hearing evaluation done by a licensed and trusted audiologist. And, yes, there are situations where one hearing aid may be indicated. But generally, when hearing loss is identified in both ears, two hearing aids is currently recognized as best practice.