Why Should I Use Two Hearing Aids Instead of One?
If you have ever had hearing aids recommended for you after having your hearing tested, you might have been surprised to hear the audiologist say “hearing aids” instead of “hearing aid”. If one ear can hear well, isn’t that enough? While that logic makes sense, there are multiple benefits of hearing binaurally (with both ears) compared to hearing monaurally (with one ear). After all, humans are equipped with 2 ears instead of 1 for a reason! If your audiologist tells you that both ears are candidates for hearing aids, here is why you should move forward with that recommendation:
If a sound comes from one side of your head, up to 10-15 decibels of that sound is blocked on its way to the opposite ear, leading to more difficulty hearing in that ear. Having a hearing aid on both ears eliminates this “head shadow” effect.
Hearing with both ears allows us to hear sounds at a quieter level, through a process called loudness summation. Think of how your depth perception is better with 2 eyes open compared to one eye. Similarly, we can hear well with the volume 2-8 decibels quieter when we are listening with both ears compared to one.
One common symptom of hearing loss is difficulty knowing which direction a sound came from, or localization. Our brains are constantly examining the details of sounds and comparing data between the right and left ears in order to localize sound. Having improved hearing in both ears allows your brain to properly measure this data and know the direction of a sound.
Hearing in background noise is especially difficult with hearing loss. This is because the signal (what we are trying to hear) is barely louder than the noise (the competing sounds around us). Hearing the same sound in both ears allows our brains to “fuse” these sounds together. The technical terms for this process are binaural squelch and binaural redundancy. Because of this fusion, the brain effectively adds 2-3 decibels to the sound source we are trying to hear, boosting it compared to the competing noise.
When wearing two hearing aids, they are programmed so that the volume transmitted into your brain from your ears is “balanced”, even if naturally one ear is worse than the other. This helps hearing aid users feel more balanced in their environments. Only wearing one hearing aid can disrupt this balance. Similarly, hearing aid users tend to report improved sound quality when wearing two hearing aids instead of one, because the brain is receiving the same type of sound through both ears.
In some cases, if one ear consistently wears a hearing aid while the other does not for a long period of time, the unaided ear’s ability to process words may decline due to the lack of acoustic information being transmitted to the brain.
We would be happy to let you see the difference for yourself. At our clinic, we offer a trial period when we fit your ears with hearing aids, as well as the ability to “demo” a pair of hearing aids before deciding to order them. We look forward to meeting you and helping you start your journey to improved hearing.
References:
Avan, P., Giraudet, F., & Büki, B. (2015). Importance of binaural hearing. Audiology & neuro-otology, 20 Suppl 1, 3–6.
Balfour, P. B., & Hawkins, D. B. (1992). A comparison of sound quality judgments for monaural and binaural hearing aid processed stimuli. Ear and hearing, 13(5), 331–339.
Cox, R. M., Schwartz, K. S., Noe, C. M., & Alexander, G. C. (2011). Preference for one or two hearing AIDS among adult patients. Ear and hearing, 32(2), 181–197.
Hawkins, D. B., Prosek, R. A., Walden, B. E., & Montgomery, A. A. (1987). Binaural loudness summation in the hearing impaired. Journal of speech and hearing research, 30(1), 37–43.
Hurley R. M. (1998). Is the unaided ear effect independent of auditory aging?. Journal of the American Academy of Audiology, 9(1), 20–24.
