Single-sided deafness, or unilateral hearing loss, is much more widespread than people realize, notably in kids.As a result, the average person sees hearing loss as a black and white — either somebody has average hearing in both ears or decreased hearing on each side, but that ignores one particular form of hearing loss completely.
A 1998 study thought that approximately 400,000 children had a unilateral hearing loss due to injury or disease in the moment. It is safe to say that number has gone up in that last two decades.
What is Single-Sided Hearing Loss and What Causes It?
As its name implies, single-sided hearing loss suggests a reduction in hearing only in one ear. The hearing loss may be conductive, sensorineural or mixed. In intense cases, profound deafness is possible. The dysfunctional ear is incapable of hearing whatsoever and that person is left with monaural audio quality — their hearing is limited to one side of the human body.
Reasons for premature hearing loss vary. It can be the result of trauma, for instance, a person standing next to a gun firing on the left might end up with moderate or profound hearing loss in that ear. A disease can lead to the problem, as well, for example:
- Acoustic neuroma
- Waardenburg syndrome
No matter the origin, an individual with unilateral hearing must adapt to a different method of processing audio.
Direction of the Sound
The brain utilizes the ears almost just like a compass. It defines the direction of noise based on what ear registers it first and at the highest volume.
With the single-sided hearing loss, the noise is only going to come in one ear no matter what direction it comes from. In case you have hearing in the left ear, then your mind will turn to look for the noise even if the person speaking is on the right.
Think for a minute what that would be similar to. The sound would enter one side no matter where what direction it comes from. How would you know where a person talking to you personally is standing? Even if the hearing loss is not deep, sound direction is catchy.
Honing in on Audio
The mind also uses the ears to filter out background noise. It tells one ear, the one closest to the sound that you wish to concentrate on, to listen to a voice. The other ear manages the background sounds. This is precisely why in a noisy restaurant, so you can still concentrate on the dialogue at the dining table.
When you can’t use that tool, the brain gets confused. It’s unable to filter out background noises like a fan running, so that is everything you hear.
The brain has a lot going on at any given 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 talking with family. With just one functioning ear, the brain loses that ability to do one thing when listening. It has to prioritize between what you hear and what you see, so you tend to miss out on the dialogue around you while you browse your newsfeed.
The Head Shadow Effect
The mind shadow effect describes how certain sounds are inaccessible to a person having a unilateral hearing loss. Low tones have extended frequencies so they bend enough to wrap around the head and reach the ear. High pitches have shorter wavelengths and don’t survive the trek.
If you’re standing next to an individual with a high pitched voice, then you might not understand what they say unless you turn so the good ear is on their side. On the flip side, you may hear someone with a deep voice just fine regardless of what side they are on because they create longer sound waves which make it to either ear.
Individuals with only slight hearing loss in just one ear tend to adapt. They learn quickly to turn their head a certain way to hear a buddy talk, for instance. For those who struggle with single-sided hearing loss, a hearing aid might be work round that yields their lateral hearing.