Selective hearing is a term that normally is used 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 actually selective hearing is quite the talent, an amazing linguistic task performed by teamwork between your brain and ears.
The Stress Of Trying to Hear in a Crowd
This situation probably feels familiar: you’re feeling burnt out from a long workday but your friends all really want to go out for dinner and drinks. They decide on the noisiest restaurant (because they have incredible food and live entertainment). And you spend an hour and a half straining your ears, attempting to follow the conversation.
But it’s challenging, and it’s taxing. This suggests that you could have hearing loss.
Maybe, you rationalize, the restaurant was simply too loud. But… everyone else seemed to be having a great time. You seemed like the only one experiencing difficulty. Which gets you thinking: what is it about the packed 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 why? Scientists have started to discover the solution, and it all begins with 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 formally called “hierarchical encoding”. Most of this process occurs in the brain. At least, that’s according to a new study performed by a team from Columbia University.
Ears work like a funnel as scientists have known for quite a while: they deliver all of the unprocessed data that they collect to your brain. In the auditory cortex the real work is then accomplished. Vibrations triggered by moving air are interpreted by this portion of the brain into recognizable sound information.
Precisely what these processes look like had remained a mystery in spite of the existing understanding of the role played by the auditory cortex in the hearing process. Thanks to some innovative research methods including participants with epilepsy, scientists at Columbia were able to learn more about how the auditory cortex works in terms of picking out voices in a crowd.
The Hearing Hierarchy
And the information they found out are as follows: there are two components of the auditory cortex that manage most of the work in helping you key in on particular voices. And in loud environments, they enable you to isolate and enhance certain voices.
- Superior temporal gyrus (STG): At some point your brain will need to make some value based decisions and this happens in the STG after it receives the voices which were previously differentiated by the HG. Which voices can be freely moved to the background and which ones you want to focused on is figured out by the STG..
- Heschl’s gyrus (HG): This is the region of the auditory cortex that handles the first stage of the sorting process. Heschl’s gyrus or HG processes each unique voice and separates them into distinguishable identities.
When you have hearing loss, your ears are lacking certain wavelengths so it’s harder for your brain to recognize voices (low or high, based upon your hearing loss). Your brain isn’t supplied with enough information to assign individual identities to each voice. It all blurs together as a result (meaning interactions will more difficult to follow).
A New Algorithm From New Science
Hearing aids currently have features that make it less difficult to hear in loud circumstances. But now that we understand what the basic process looks like, hearing aid companies can incorporate more of those natural functions into their device algorithms. As an example, you will have a better capacity to hear and understand what your coworkers are saying with hearing aids that assist the Heshl’s gyrus and do a little more to distinguish voices.
Technology will get better at mimicking what takes place in nature as we learn more about how the brain really works in combination with the ears. And that can result in better hearing success. That way, you can concentrate a little less on straining to hear and a little more on enjoying yourself.