Sometimes when an individual has a difficult time hearing, somebody close to them insultingly says they have “selective hearing”. Perhaps you heard your mother suggest that your father had “selective hearing” when she suspected he might be ignoring her.
But it turns out that selective hearing is quite the skill, an amazing linguistic task carried out by cooperation between your brain and ears.
The Difficulty Of Trying to Hear in a Crowd
Maybe you’ve dealt with this situation before: you’re feeling burnt out from a long workday but your friends all really would like to go out for dinner and drinks. And of course, they want to go to the loudest restaurant (because it’s trendy and the food is the best in town). And you strain and struggle to follow the conversation for the entire evening.
But it’s very difficult and exhausting. This suggests that you could have hearing loss.
Maybe, you rationalize, the restaurant was just too loud. But no one else seemed to be having difficulties. The only one who appeared to be having difficulty was you. Which gets you thinking: 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 what’s the reason? The answer, according to scientists, is selective hearing.
How Does Selective Hearing Operate?
The scientific name for what we’re loosely calling selective hearing is “hierarchical encoding,” and it doesn’t happen in your ears at all. The majority of this process happens in the brain. At least, that’s according to a new study performed by a team at Columbia University.
Ears work just like a funnel as scientists have recognized for quite a while: they forward 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 translated by this portion of the brain into recognizable sound information.
Because of significant research with CT and MRI scans, scientists have understood for years that the auditory cortex plays a significant role in hearing, but they were stumped regarding what those processes actually look like. Thanks to some novel research techniques including participants with epilepsy, scientists at Columbia were able to discover more about how the auditory cortex works in terms of picking out voices in a crowd.
The Hearing Hierarchy
And the facts they discovered follows: most of the work accomplished by the auditory cortex to isolate particular voices is performed by two separate regions. And in loud situations, they allow you to separate and boost particular voices.
- Superior temporal gyrus (STG): Sooner or later your brain will need to make some value based choices and this is done in the STG once it receives the voices which were previously separated by the HG. Which voices can be safely 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 region of the auditory cortex. Heschl’s gyrus or HG processes each individual voice and separates them into distinct identities.
When you have hearing problems, your ears are missing particular wavelengths so it’s more difficult for your brain to recognize voices (high or low, based upon your hearing loss). Your brain isn’t supplied with enough information to assign separate identities to each voice. It all blurs together as a result (which makes discussions hard to follow).
A New Algorithm From New Science
Hearing aids currently have functions that make it easier to hear in loud circumstances. But now that we know what the fundamental process looks like, hearing aid manufacturers can integrate more of those natural operations into their instrument algorithms. For example, you will have a better capacity to hear and understand what your coworkers are talking about with hearing aids that help the Heshl’s gyrus and do a little more to separate voices.
The more we discover about how the brain works, particularly in conjunction with the ears, the better new technology will be able to mimic what happens in nature. And that can lead to better hearing success. That way, you can focus a little less on straining to hear and a little more on enjoying yourself.