Selective hearing is a term that frequently gets tossed about as a pejorative, an insult. Maybe you heard your mother accuse your father of having “selective hearing” when she thought he was ignoring her.
But actually it takes an amazing act of teamwork between your ears and your brain to have selective hearing.
Hearing in a Crowd
This situation probably seems familiar: you’ve been through a long day at work, but your friends all insist on meeting up for dinner. They pick 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 challenging, and it’s taxing. And it’s an indication of hearing loss.
Maybe, you rationalize, the restaurant was simply too noisy. But… everyone else seemed to be having a great time. It seemed like you were the only one having trouble. Which gets you thinking: what is it about the crowded room, the cacophony of voices all battling to be heard, that throws hearing-impaired ears for a loop? It seems as if hearing well in a crowd is the first thing to go, but what’s the reason? Scientists have begun to reveal the solution, and it all begins with selective hearing.
How Does Selective Hearing Operate?
The phrase “selective hearing” is a task that doesn’t even occur in the ears and is scientifically known as “hierarchical encoding”. This process almost completely happens in your brain. At least, that’s according to a new study done by a team at Columbia University.
Scientists have recognized for quite a while that human ears effectively work like a funnel: they gather all the signals and then deliver the raw information to your brain. That’s where the heavy lifting takes place, specifically the auditory cortex. Vibrations caused by moving air are interpreted by this portion of the brain into recognizable sound information.
Exactly what these processes look like was still unknown in spite of the established understanding of the role played by the auditory cortex in the hearing process. Thanks to some innovative research techniques including participants with epilepsy, scientists at Columbia were able to discover more about how the auditory cortex functions in relation to discerning voices in a crowd.
The Hierarchy of Hearing
And the information they found out are as follows: there are two components of the auditory cortex that accomplish most of the work in helping you key in on distinct voices. They’re what enables you to sort and intensify particular voices in noisy settings.
- Heschl’s gyrus (HG): The first sorting stage is taken care of by this region of the auditory cortex. Scientists discovered that the Heschl’s gyrus (we’re just going to call it HG from here on out) was breaking down each individual voice, separating them via individual identities.
- Superior temporal gyrus (STG): The differentiated voices move from the HG to the STG, and it’s at this point that your brain starts to make some value distinctions. Which voices can be freely moved to the background and which ones you want to pay attention to is figured out by the STG..
When you have hearing impairment, your ears are lacking specific wavelengths so it’s harder for your brain to recognize voices (depending on your hearing loss it could be low or high frequencies). Your brain isn’t furnished with enough data to assign individual identities to each voice. As a result, it all blurs together (which makes discussions hard to follow).
A New Algorithm From New Science
Hearing aids already have functions that make it easier to hear in loud settings. But now that we know what the fundamental process looks like, hearing aid makers can integrate more of those natural operations into their device algorithms. As an example, hearing aids that do more to differentiate voices can assist the Heschl’s gyrus a little bit, bringing about a better ability for you to comprehend what your coworkers are saying in that loud restaurant.
Technology will get better at mimicking what happens in nature as we uncover more about how the brain works in conjunction with the ears. And better hearing outcomes will be the outcome. Then you can concentrate a little more on enjoying yourself and a little less on straining to hear.
