Selective hearing is a phrase that commonly is used as a pejorative, an insult. When your mother used to accuse you of having “selective hearing,” she meant that you listened to the part about chocolate cake for dessert and (maybe deliberately) ignored the bit about doing your chores.
But in reality it takes an incredible act of teamwork between your ears and your brain to have selective hearing.
The Stress Of Trying to Hear in a Crowd
This situation potentially seems familiar: you’re feeling tired from a long day at work but your friends all really would like to go out for dinner and drinks. And naturally, they want to go to the loudest restaurant (because they have amazing food and live entertainment). And you spend the entire evening straining your ears, attempting to follow the conversation.
But it’s very difficult and exhausting. And it’s an indication of hearing loss.
You think, perhaps the restaurant was just too loud. But no one else appeared to be struggling. The only person who appeared to be having difficulty was you. Which makes you think: Why do ears that have 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? The answer, as reported by scientists, is selective hearing.
Selective Hearing – How Does it Work?
The phrase “selective hearing” is a process that doesn’t even occur in the ears and is scientifically known as “hierarchical encoding”. The majority of this process occurs in the brain. At least, that’s as reported by a new study done by a team from Columbia University.
Scientists have recognized for quite a while that human ears essentially work as a funnel: they send all of the raw data that they gather to your brain. That’s where the heavy lifting happens, specifically the auditory cortex. That’s the part of your gray matter that handles all those signals, interpreting impressions of moving air into perceptible sounds.
Precisely what these processes look like was still unknown in spite of the existing knowledge of the role played by the auditory cortex in the hearing process. Thanks to some unique research techniques including participants with epilepsy, scientists at Columbia were able to find out more about how the auditory cortex works in terms of discerning voices in a crowd.
The Hearing Hierarchy
And the insight they discovered are as follows: there are two parts of the auditory cortex that manage most of the work in helping you identify specific voices. And in noisy environments, they allow you to isolate and boost certain voices.
- Heschl’s gyrus (HG): The first sorting stage 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.
- Superior temporal gyrus (STG): The differentiated voices move from the HG to the STG, and it’s at this point that your brain starts to make some value determinations. The superior temporal gyrus figures out which voices you want to pay attention to and which can be safely moved to the background.
When you start to suffer with hearing problems, it’s more difficult for your brain to distinguish voices because your ears are lacking specific wavelengths of sound (high or low, depending on your hearing loss). Your brain isn’t provided with enough information to assign separate identities to each voice. Consequently, it all blends together (which makes interactions hard to follow).
A New Algorithm From New Science
It’s common for hearing aids to have features that make it easier to hear in a crowd. But hearing aid manufacturers can now include more of those natural functions into their algorithms because they have a greater concept of what the process looks like. For example, you will have a greater capacity to hear and comprehend what your coworkers are talking about with hearing aids that help the Heshl’s gyrus and do a little more to differentiate voices.
The more we learn about how the brain works, particularly in connection with the ears, the better new technology will be capable of mimicking what happens in nature. And that can result in better hearing outcomes. That way, you can concentrate a little less on struggling to hear and a little more on enjoying yourself.