Sometimes when a person 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 thought he was ignoring her.
But actually selective hearing is quite the ability, an impressive linguistic task executed by teamwork 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 day at work but your friends all really would like to go out for dinner and drinks. They decide on the loudest restaurant (because it’s trendy and the food is the best in town). And you spend the entire evening straining your ears, attempting to follow the conversation.
But it’s very difficult and exhausting. This indicates that you could have hearing loss.
You think, maybe the restaurant was simply too noisy. But… everyone else seemed to be having a fine go of it. You seemed like the only one experiencing difficulty. So you begin to ask yourself: Why do ears with hearing impairment have such a hard time with the noise of a crowded room? Why is it that being able to hear in a crowd is so challenging? Scientists have begun to discover the solution, and it all begins with 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 in line with a new study done by a team from Columbia University.
Scientists have recognized for some time that human ears essentially work like a funnel: they collect all the signals and then send the raw information to your brain. In the auditory cortex the real work is then accomplished. Vibrations caused by moving air are interpreted by this portion of the brain into recognizable sound information.
Because of significant research with CT and MRI scans, scientists have recognized for years that the auditory cortex plays a significant role in hearing, but they were clueless regarding what those processes really look like. Thanks to some unique research techniques including participants with epilepsy, scientists at Columbia were able to discover more about how the auditory cortex functions in terms of discerning voices in a crowd.
The Hierarchy of Hearing
And here’s what these intrepid scientists discovered: most of the work performed by the auditory cortex to isolate particular voices is accomplished by two separate parts. And in loud settings, they enable you to isolate and intensify particular voices.
- Superior temporal gyrus (STG): At some point your brain will need to make some value based decisions and this occurs in the STG once 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 determined by the STG..
- Heschl’s gyrus (HG): The first sorting phase is taken care of by this region of the auditory cortex. Researchers found that the Heschl’s gyrus (we’re simply going to call it HG from here on out) was breaking down each distinct voice, classifying them via unique identities.
When you start to suffer with hearing damage, it’s harder for your brain to identify voices because your ears are lacking certain wavelengths of sound (low or high, based upon your hearing loss). Your brain isn’t given enough data to assign separate identities to each voice. As a result, it all blurs together (which makes discussions tough to follow).
A New Algorithm From New Science
Hearing aids currently have functions that make it less difficult to hear in loud environments. But hearing aid manufacturers can now incorporate more of those natural functions into their algorithms because they have a better concept of what the process looks like. For instance, hearing aids that do more to distinguish voices can assist the Heschl’s gyrus a little bit, leading to a better capacity for you to understand what your coworkers are talking about in that loud restaurant.
Technology will get better at mimicking what takes place in nature as we uncover more about how the brain functions in conjunction with the ears. And better hearing outcomes will be the outcome. That way, you can focus a little less on straining to hear and a little more on enjoying yourself.