Unilateral hearing loss, or single sided deafness, is much more prevalent than people realize, prominently in kids. Age-related hearing loss, which affects many adults at some point, tends to become lateral, to put it simply, it affects both ears to a extent. As a result, the average person sees hearing loss as a black and white — someone has typical hearing in both ears or reduced hearing on both sides, but that ignores one form of hearing loss altogether.
A 1998 study estimated around 400,000 kids had a unilateral hearing loss due to trauma or disease at the time. It is safe to say this number has gone up in that past two decades.
What’s Single-Sided Hearing Loss and What Causes It?
As the name implies, single-sided hearing loss suggests a decrease in hearing only in one ear. The hearing loss may be conductive, sensorineural or mixed. In extreme instances, profound deafness is possible. The nonfunctioning ear is incapable of hearing whatsoever and that person is left with monaural audio quality — their hearing is limited to a side of the body.
Causes of unilateral hearing loss vary. It may be caused by injury, for instance, a person standing next to a gun fire on the left may get moderate or profound hearing loss in that ear. A disease may lead to this issue, as well, such as:
- Acoustic neuroma
- Waardenburg syndrome
No matter the cause, an individual with unilateral hearing must adapt to a different method of processing audio.
Management of the Audio
The brain uses the ears nearly like a compass. It defines the direction of sound based on which ear registers it initially and in the maximum volume. When somebody talks to you while positioned on the left, the brain sends a signal to turn in that way.
With the single-sided hearing loss, the noise will only come in one ear no matter what way it comes from. If you have hearing in the left ear, your mind will turn to search for the sound even when the person talking is on the right.
Think for a minute what that would be similar to. The sound would enter 1 side no matter where what direction it comes from. How would you know where an individual talking to you personally is standing? Even if the hearing loss is not profound, sound management is tricky.
Focusing on Sound
The mind also uses the ears to filter out background sound. It tells one ear, the one nearest to the sound that you wish to focus on, to listen to a voice. The other ear manages the background sounds. This is why at a noisy restaurant, so you can still concentrate on the conversation at the table.
When you don’t have that tool, the brain gets confused. It’s not able to filter out background noises like a fan blowing, so that is all you hear.
The Ability to Multitask
The brain has a lot happening at any one time but having use of two ears allows it to multitask. That is why you can sit and read your social media sites whilst watching TV or having a conversation. With just one working ear, the brain loses that ability to do one thing when listening. It has to prioritize between what you hear and what you see, which means you usually lose out on the conversation taking place without you while you navigate your newsfeed.
The Head Shadow Impact
The mind shadow effect clarifies how certain sounds are inaccessible to a person having a unilateral hearing loss. Low tones have extended frequencies so they bend enough to wrap round the head and reach the ear. High pitches have shorter wavelengths and do not survive the journey.
If you’re standing next to an individual with a high pitched voice, you may not know what they say unless you flip so the working ear is on their side. On the flip side, you might hear someone with a deep voice just fine regardless of what side they’re on because they create longer sound waves that make it to either ear.
People with only minor hearing loss in only one ear have a tendency to accommodate. They learn quickly to turn their head a certain way to listen to a buddy speak, for instance. For those who struggle with single-sided hearing loss, a hearing aid might be work round that returns their lateral hearing to them.