Selective hearing is a term that normally gets tossed about as a pejorative, an insult. Perhaps you heard your mother suggest that your father had “selective hearing” when she thought he was ignoring her.
But actually it takes an amazing act of cooperation between your ears and your brain to have selective hearing.
The Stress Of Trying to Hear in a Crowd
Maybe you’ve encountered this scenario before: you’re feeling burnt out from a long workday but your friends all really want to go out for dinner and drinks. They choose the loudest restaurant (because it’s popular and the deep-fried cauliflower is the best in town). And you strain and struggle to follow the conversation for the entire evening.
But it’s tough, and it’s taxing. This indicates that you may have hearing loss.
Perhaps, you rationalize, the restaurant was simply too loud. But no one else appeared to be struggling. It seemed like you were the only one experiencing difficulty. Which makes you think: what is it about the crowded room, the cacophony of voices all trying to be heard, that causes hearing impaired ears to struggle? It seems like hearing well in a crowded place is the first thing to go, but what’s the reason? The solution, as reported by scientists, is selective hearing.
Selective Hearing – How Does it Work?
The term “selective hearing” is a task that doesn’t even occur in the ears and is scientifically known as “hierarchical encoding”. This process almost entirely takes place in your brain. At least, that’s according to a new study performed by a team at Columbia University.
Scientists have known for some time that human ears effectively work as a funnel: they forward all of the unprocessed data that they gather to your brain. In the auditory cortex the real work is then done. Vibrations triggered by moving air are translated by this portion of the brain into perceptible sound information.
Because of substantial research with MRI and CT scans, scientists have understood 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. Thanks to some novel research techniques including participants with epilepsy, scientists at Columbia were able to find out more about how the auditory cortex works in relation to discerning voices in a crowd.
The Hierarchy of Hearing
And here’s what these intrepid scientists found out: the majority of the work done by the auditory cortex to pick out particular voices is performed by two separate parts. They’re what enables you to sort and enhance particular voices in loud environments.
- Heschl’s gyrus (HG): This is the region of the auditory cortex that handles the first phase of the sorting process. Heschl’s gyrus or HG processes each individual voice and separates them into discrete identities.
- Superior temporal gyrus (STG): The separated voices go from the HG to the STG, and it’s here that your brain starts to make some value determinations. Which voices can be comfortably 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 (low or high, depending on your hearing loss). Your brain isn’t provided with enough information to assign separate identities to each voice. Consequently, it all blurs together (which makes discussions hard to follow).
New Science = New Algorithm
It’s standard for hearing aids to have functions that make it easier to hear in a crowd. But hearing aid manufacturers can now include more of those natural functions into their algorithms because they have a greater concept of what the process looks like. As an example, hearing aids that do more to identify 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 noisy restaurant.
Technology will get better at mimicking what happens in nature as we learn more about how the brain really works in conjunction with the ears. And better hearing success will be the outcome. Then you can concentrate a little more on enjoying yourself and a little less on straining to hear.