Selective hearing is a term that usually gets tossed about as a pejorative, an insult. When your mother used to accuse you of having “selective hearing,” she was suggesting that you paid attention to the part about chocolate cake for dessert and (maybe purposely) disregarded the part about doing your chores.
But actually selective hearing is quite the ability, an impressive linguistic feat performed by teamwork between your ears and brain.
The Difficulty Of Trying to Hear in a Crowd
This situation potentially seems familiar: you’ve been through a long day at work, but your friends all insist on meeting up for dinner. They decide on the noisiest restaurant (because it’s trendy and the food is the best in town). And you strain and struggle to understand the conversation for the entire evening.
But it’s very difficult and exhausting. This suggests that you might have hearing loss.
Perhaps, you rationalize, the restaurant was simply too loud. But no one else seemed to be struggling. You seemed like the only one experiencing difficulty. Which makes you think: what is it about the packed room, the cacophony of voices all trying to be heard, that throws hearing-impaired ears for a loop? 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 phrase “selective hearing” is a process that doesn’t even take place in the ears and is formally known as “hierarchical encoding”. This process almost exclusively occurs in your brain. At least, that’s in accordance with a new study done by a team from Columbia University.
Scientists have known for quite some time that human ears effectively work like a funnel: they collect all the signals and then forward the raw information to your brain. That’s where the heavy lifting occurs, specifically the auditory cortex. Vibrations caused by moving air are interpreted by this portion of the brain into recognizable sound information.
Just what these processes look like was still unknown despite the established understanding of the role played by the auditory cortex in the process of hearing. Scientists were able, by making use of unique research techniques on individuals with epilepsy, to get a better picture of how the auditory cortex picks out voices in a crowd.
The Hearing Hierarchy
And here is what these intrepid scientists discovered: there are two regions of the auditory cortex that do most of the work in helping you key in on distinct voices. They’re what enables you to separate and enhance specific voices in loud settings.
- Heschl’s gyrus (HG): The first sorting stage is taken care of by this region of the auditory cortex. Heschl’s gyrus or HG processes each unique voice and separates them into discrete identities.
- Superior temporal gyrus (STG): The differentiated voices move from the HG to the STG, and it’s at this point that your brain begins to make some value distinctions. Which voices can be safely moved to the background and which ones you want to pay attention to is figured out by the STG..
When you begin to suffer from hearing problems, it’s harder for your brain to identify voices because your ears are missing particular wavelengths of sound (depending on your hearing loss it might be high or low frequencies). Your brain can’t assign individual identities to each voice because it doesn’t have enough data. Consequently, it all blends together (which makes interactions tough to follow).
A New Algorithm From New Science
It’s typical for hearing aids to have features that make it easier to hear in a crowd. But now that we know what the basic process looks like, hearing aid companies can incorporate more of those natural functions into their device algorithms. For instance, hearing aids that do more to distinguish voices can assist the Heschl’s gyrus a little bit, leading to a greater capacity for you to understand what your coworkers are talking about in that noisy restaurant.
Technology will get better at mimicking what occurs in nature as we uncover more about how the brain really works in combination with the ears. And that can lead to improved hearing success. Then you can concentrate a little more on enjoying yourself and a little less on straining to hear.