Sometimes when an individual has a difficult time hearing, someone close to them insultingly suggests they have “selective hearing”. Maybe you heard your mother suggest that your father had “selective hearing” when she believed he might be ignoring her.
But actually selective hearing is quite the talent, an impressive linguistic accomplishment performed by cooperation between your brain and ears.
The Stress Of Trying to Hear in a Crowd
Perhaps you’ve encountered this scenario before: you’ve had a long day at work, but your friends all insist on going out to dinner. And naturally, they want to go to the loudest restaurant (because it’s popular and the food is the best in town). And you spend the entire evening straining your ears, attempting to follow the conversation.
But it’s difficult, and it’s taxing. This suggests that you may have hearing loss.
You think, maybe the restaurant was just too loud. But no one else seemed to be having difficulties. You seemed like the only one experiencing trouble. Which makes you think: Why do ears that have hearing impairment have such a hard time with the noise of a packed room? It seems like hearing well in a crowded place is the first thing to go, but why? The solution, according to scientists, is selective hearing.
How Does Selective Hearing Function?
The scientific term for what we’re broadly calling selective hearing is “hierarchical encoding,” and it doesn’t happen inside of your ears at all. This process almost entirely occurs in your brain. At least, that’s in line with a new study done by a team at Columbia University.
Scientists have known for quite some time that human ears effectively work like a funnel: they gather all the impulses and then deliver the raw data to your brain. In the auditory cortex the real work is then accomplished. Vibrations caused by moving air are translated by this part of the brain into recognizable sound information.
Exactly what these processes look like had remained a mystery despite the existing understanding of the role played by the auditory cortex in the process of hearing. Thanks to some innovative research techniques concerning participants with epilepsy, scientists at Columbia were able to find out more about how the auditory cortex works in relation to picking out voices in a crowd.
The Hearing Hierarchy
And the information they discovered follows: the majority of the work done by the auditory cortex to pick out distinct voices is accomplished by two different parts. And in loud environments, they allow you to separate and enhance particular voices.
- Superior temporal gyrus (STG): Sooner or later your brain will need to make some value based decisions and this occurs in the STG after it receives the voices which were previously separated by the HG. Which voices can be comfortably moved to the background and which ones you want to focused on is determined by the STG..
- Heschl’s gyrus (HG): The first sorting phase is handled by this part of the auditory cortex. Heschl’s gyrus or HG breaks down each individual voice and separates them into distinguishable identities.
When you begin to suffer from hearing problems, it’s harder for your brain to differentiate voices because your ears are missing specific wavelengths of sound (depending on your hearing loss it could be low or high frequencies). Your brain can’t assign individual identities to each voice because it doesn’t have enough information. It all blends together as a result (which means interactions will more difficult to understand).
A New Algorithm From New Science
Hearing aids already have functions that make it less difficult to hear in noisy circumstances. But now that we know what the basic process looks like, hearing aid manufacturers can incorporate more of those natural functions into their instrument algorithms. For example, you will have a greater capacity to hear and comprehend what your coworkers are saying with hearing aids that assist the Heshl’s gyrus and do a little more to identify voices.
The more we find out about how the brain works, especially in combination with the ears, the better new technology will be capable of mimicking what takes place in nature. And that can lead to improved hearing success. That way, you can focus a little less on straining to hear and a little more on enjoying yourself.