Selective hearing is a term that commonly gets tossed about as a pejorative, an insult. Perhaps you heard your mother suggest that your father had “selective hearing” when she suspected he might be ignoring her.
But in reality it takes an amazing act of teamwork between your brain and your ears to have selective hearing.
Hearing in a Crowd
Maybe you’ve encountered this scenario 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 pick the noisiest restaurant (because it’s popular 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 tough, and it’s taxing. This indicates that you might have hearing loss.
You think, maybe the restaurant was just 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: Why do ears with hearing impairment have such a hard time with the noise of a packed room? Just why is it that being able to hear in a crowd is so challenging? Scientists have begun to uncover the answer, and it all begins with selective hearing.
Selective Hearing – How Does it Work?
The phrase “selective hearing” is a task that doesn’t even occur in the ears and is scientifically known as “hierarchical encoding”. Most of this process happens in the brain. At least, that’s as reported by a new study carried out by a team at Columbia University.
Scientists have recognized for quite some time that human ears essentially work as a funnel: they forward all of the unprocessed data that they collect to your brain. That’s where the real work occurs, particularly the auditory cortex. Vibrations triggered by moving air are interpreted by this portion of the brain into recognizable sound information.
Precisely what these processes look like was still unknown despite the established knowledge of the role played by the auditory cortex in the hearing process. Scientists were able, by using unique research techniques on people with epilepsy, to get a better understanding of how the auditory cortex picks out voices in a crowd.
The Hierarchy of Hearing
And the insight 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 specific voices. They’re what enables you to sort and amplify particular voices in noisy settings.
- Superior temporal gyrus (STG): At some point your brain will need to make some value based decisions and this is done in the STG after it receives the voices that were previously differentiated by the HG. The superior temporal gyrus figures out which voices you want to give attention to and which can be safely moved to the background.
- Heschl’s gyrus (HG): The first sorting phase is handled by this part of the auditory cortex. Heschl’s gyrus or HG processes each unique voice and separates them into distinguishable identities.
When you start to suffer from hearing problems, it’s more difficult for your brain to identify voices because your ears are missing particular 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 blurs together as a result (which makes conversations hard to follow).
A New Algorithm From New Science
Hearing aids already have functions that make it easier to hear in loud circumstances. But hearing aid makers can now incorporate more of those natural functions into their algorithms because they have a better concept of what the process looks like. For instance, hearing aids that do more to differentiate voices can help out the Heschl’s gyrus a little, resulting in a greater ability for you to comprehend what your coworkers are saying in that loud restaurant.
The more we find out about how the brain works, particularly in combination with the ears, the better new technology will be able to mimic what happens in nature. And better hearing success will be the outcome. That way, you can focus a little less on struggling to hear and a little more on enjoying yourself.