Sometimes when an individual has a hard time hearing, somebody close to them insultingly says they have “selective hearing”. When your mother used to accuse you of having “selective hearing,” she was suggesting that you listened to the part about going to the fair and (perhaps intentionally) ignored the part about doing your chores.
But it turns out that selective hearing is quite the talent, an impressive linguistic feat conducted by cooperation between your brain and ears.
The Difficulty Of Trying to Hear in a Crowd
This situation potentially seems familiar: 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 they have incredible food and live entertainment). And you spend the entire evening straining your ears, working hard to follow the conversation.
But it’s very difficult and exhausting. And it’s an indication of hearing loss.
You think, maybe the restaurant was simply too noisy. But no one else appeared to be having difficulties. You seemed like the only one having difficulty. So you start to ask yourself: what is it about the packed 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.
How Does Selective Hearing Function?
The scientific term for what we’re loosely calling selective hearing is “hierarchical encoding,” and it doesn’t take place in your ears at all. This process almost completely occurs in your brain. At least, that’s in line with a new study done by a team at Columbia University.
Scientists have recognized for some time that human ears basically work like a funnel: they send all of the unprocessed data that they gather to your brain. That’s where the real work takes place, particularly the auditory cortex. Vibrations triggered by moving air are interpreted by this portion of the brain into perceptible sound information.
Because of significant research with CT and MRI scans, scientists have recognized for years that the auditory cortex plays a substantial role in hearing, but they were stumped regarding what those processes actually look like. Thanks to some unique research methods including participants with epilepsy, scientists at Columbia were able to discover more about how the auditory cortex works in relation to picking out voices in a crowd.
The Hierarchy of Hearing
And here is what these intrepid scientists learned: there are two components of the auditory cortex that accomplish most of the work in helping you key in on particular voices. And in loud environments, they enable you to isolate and amplify certain voices.
- Superior temporal gyrus (STG): The separated voices move from the HG to the STG, and it’s here that your brain begins to make some value determinations. 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): This is the region of the auditory cortex that deals with the first stage of the sorting process. Scientists found that the Heschl’s gyrus (we’re just going to call it HG from now on) was breaking down each individual voice, classifying them into individual identities.
When you have hearing impairment, your ears are missing specific wavelengths so it’s more difficult for your brain to recognize voices (high or low, based upon your hearing loss). Your brain can’t assign individual identities to each voice because it doesn’t have enough data. Consequently, it all blurs together (which makes discussions tough to follow).
A New Algorithm From New Science
Hearing aids already have functions that make it easier to hear in loud environments. But hearing aid manufacturers can now integrate more of those natural functions into their algorithms because they have a greater concept of what the process looks like. As an example, you will have a better capacity to hear and comprehend what your coworkers are saying with hearing aids that help the Heshl’s gyrus and do a little more to separate 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 result in improved hearing outcomes. That way, you can focus a little less on struggling to hear and a little more on enjoying yourself.