Sometimes when an individual has a hard time hearing, someone close to them insultingly says they have “selective hearing”. Perhaps you heard your mother accuse your father of having “selective hearing” when she believed he might be ignoring her.
But actually selective hearing is quite the skill, an amazing linguistic accomplishment conducted by cooperation between your ears and brain.
Hearing in a Crowd
Perhaps you’ve experienced this situation before: you’re feeling burnt out from a long day at work but your friends all really would like to go out for dinner and drinks. They decide on the noisiest restaurant (because they have amazing food and live entertainment). And you strain and struggle to follow the conversation for the entire evening.
But it’s difficult, and it’s taxing. And it’s a sign of hearing loss.
You think, perhaps the restaurant was simply too loud. But no one else seemed to be having difficulties. You seemed like the only one having difficulty. So you begin to ask yourself: Why do ears with hearing impairment have such a difficult time with the noise of a crowded room? It seems like hearing well in a crowd is the first thing to go, but why? The answer, according to scientists, is selective hearing.
How Does Selective Hearing Operate?
The phrase “selective hearing” is a task that doesn’t even take place in the ears and is technically known as “hierarchical encoding”. The majority of this process happens in the brain. At least, that’s according to a new study done by a team at Columbia University.
Scientists have recognized for quite some time that human ears effectively work like a funnel: they deliver all of the unprocessed data that they collect to your brain. That’s where the heavy lifting occurs, particularly the auditory cortex. That’s the part of your brain that handles all those impulses, translating sensations of moving air into identifiable sounds.
Because of extensive research with MRI and CT scans, scientists have known for years that the auditory cortex plays a considerable role in hearing, but they were clueless when it came to what those processes actually look like. Scientists were able, by utilizing unique research techniques on individuals with epilepsy, to get a better picture of how the auditory cortex discerns voices in a crowd.
The Hierarchy of Hearing
And the facts they discovered follows: there are two regions of the auditory cortex that manage most of the work in allowing you to identify distinct voices. They’re what enables you to separate and enhance distinct voices in loud settings.
- Superior temporal gyrus (STG): The differentiated voices go from the HG to the STG, and it’s here that your brain begins to make some value distinctions. Which voices can be safely moved to the background and which ones you want to pay attention to is determined by the STG..
- Heschl’s gyrus (HG): The first sorting phase is managed by this region of the auditory cortex. Heschl’s gyrus or HG processes each individual voice and separates them into discrete identities.
When you have hearing impairment, your ears are missing particular wavelengths so it’s harder for your brain to differentiate voices (depending on your hearing loss it could be low or high frequencies). Your brain can’t assign separate identities to each voice because it doesn’t have enough information. As a result, it all blends together (meaning discussions will harder to understand).
New Science = New Algorithm
It’s standard for hearing aids to have features that make it easier to hear in a crowd. But hearing aid manufacturers can now incorporate more of those natural functions into their algorithms because they have a better concept of what the process looks like. For example, you will have a better ability to hear and understand what your coworkers are saying with hearing aids that assist the Heshl’s gyrus and do a little more to identify voices.
Technology will get better at mimicking what takes place in nature as we discover more about how the brain works in conjunction with the ears. And that can lead to better hearing success. That way, you can concentrate a little less on struggling to hear and a little more on enjoying yourself.