Sometimes when an individual has a hard time hearing, somebody close to them insultingly suggests they have “selective hearing”. Maybe you heard your mother accuse your father of having “selective hearing” when she thought he might be ignoring her.
But actually selective hearing is quite the talent, an amazing linguistic task executed by cooperation between your brain and ears.
The Stress Of Trying to Hear in a Crowd
This scenario potentially seems familiar: you’re feeling burnt out from a long workday but your friends all really would like to go out for dinner and drinks. They pick the loudest restaurant (because it’s trendy and the deep-fried cauliflower is delicious). And you spend an hour and a half straining your ears, attempting to follow the conversation.
But it’s very difficult and exhausting. And it’s a sign of hearing loss.
You think, perhaps the restaurant was simply too loud. But… everyone else seemed to be having a fine go of it. The only one who appeared to be having trouble was you. Which makes you think: what is it about the crowded room, the cacophony of voices all struggling to be heard, that throws hearing-impaired ears for a loop? It seems as if hearing well in a crowded place is the first thing to go, but what’s the reason? The answer, according to scientists, is selective hearing.
Selective Hearing – How Does it Work?
The phrase “selective hearing” is a task that doesn’t even take place in the ears and is technically called “hierarchical encoding”. This process nearly completely happens in your brain. At least, that’s according to a new study carried out by a team at Columbia University.
Ears work just like a funnel as scientists have known for some time: they collect all the impulses and then forward the raw information to your brain. In the auditory cortex the real work is then done. Vibrations triggered by moving air are interpreted by this part of the brain into perceptible sound information.
Because of comprehensive research with CT and MRI scans, scientists have recognized for years that the auditory cortex plays a crucial role in hearing, but they were clueless with regards to what those processes really look like. Scientists were able, by making use of unique research techniques on people with epilepsy, to get a better understanding of how the auditory cortex discerns voices in a crowd.
The Hierarchy of Hearing
And here is what these intrepid scientists found: there are two regions of the auditory cortex that perform most of the work in helping you key in on specific voices. They’re what allows you to sort and amplify particular voices in noisy settings.
- Superior temporal gyrus (STG): Eventually your brain will need to make some value based choices and this happens in the STG after it receives the voices which were previously separated by the HG. Which voices can be freely 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 part of the auditory cortex. Researchers observed that the Heschl’s gyrus (we’re simply going to call it HG from here on out) was processing each individual voice, separating them via individual identities.
When you start to suffer from hearing problems, it’s more difficult for your brain to identify voices because your ears are lacking certain wavelengths of sound (high or low, depending on your hearing loss). Your brain can’t assign separate identities to each voice because it doesn’t have enough data. It all blends together as a consequence (which means discussions will harder to follow).
A New Algorithm From New Science
Hearing aids already have features that make it easier to hear in noisy situations. But hearing aid makers can now integrate more of those natural functions into their algorithms because they have a better idea of what the process looks like. For instance, you will have a greater 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 differentiate voices.
Technology will get better at mimicking what occurs in nature as we discover more about how the brain functions in combination with the ears. And better hearing success will be the outcome. That way, you can focus a little less on straining to hear and a little more on enjoying yourself.