Hearing Assessment Center, LLC - Lutherville, Bel Air, and  Nottingham, MD

Man can't hear in a crowded restaurant.

Sometimes when a person has a difficult time hearing, someone close to them insultingly suggests they have “selective hearing”. Perhaps you heard your mother accuse your father of having “selective hearing” when she believed he was ignoring her.

But in reality it takes an incredible act of teamwork between your ears and your brain to have selective hearing.

The Difficulty Of Trying to Hear in a Crowd

Maybe you’ve encountered this scenario before: 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 it’s popular and the deep-fried cauliflower is delicious). And you strain and struggle to follow the conversation for over an hour and a half.

But it’s very difficult and exhausting. And it’s an indication of hearing loss.

Perhaps, you rationalize, the restaurant was just too noisy. But no one else seemed to be having difficulties. You seemed like the only one having trouble. Which gets you thinking: what is it about the crowded room, the cacophony of voices all battling to be heard, that causes hearing impaired ears to struggle? It seems as if hearing well in a crowded place is the first thing to go, but why? Scientists have begun to reveal the answer, and it all begins with 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 inside of your ears at all. The majority of this process happens in the brain. At least, that’s as reported by a new study done by a team at Columbia University.

Scientists have recognized for some time that human ears essentially work like a funnel: they forward all of the raw data that they gather to your brain. In the auditory cortex the real work is then done. Vibrations triggered by moving air are interpreted by this portion of the brain into recognizable sound information.

Exactly what these processes look like had remained a mystery despite the existing understanding of the role played by the auditory cortex in the process of hearing. Thanks to some novel research techniques concerning participants with epilepsy, scientists at Columbia were able to find out more about how the auditory cortex works in relation to discerning voices in a crowd.

The Hierarchy of Hearing

And here is what these intrepid scientists discovered: the majority of the work performed by the auditory cortex to isolate specific voices is accomplished by two different parts. They’re what enables you to separate and intensify specific voices in loud situations.

  • Heschl’s gyrus (HG): The first sorting phase is managed by this part of the auditory cortex. Scientists discovered that the Heschl’s gyrus (we’re simply going to call it HG from here on out) was processing each distinct voice, separating them via unique identities.
  • Superior temporal gyrus (STG): At some point your brain will need to make some value based choices and this happens in the STG after it receives the voices that were previously separated by the HG. The superior temporal gyrus determines which voices you want to pay attention to and which can be securely moved to the background.

When you have hearing problems, your ears are missing certain wavelengths so it’s more difficult for your brain to distinguish voices (high or low, depending on your hearing loss). Your brain can’t assign separate identities to each voice because it doesn’t have enough data. It all blends together as a consequence (which makes discussions difficult to follow).

New Science = New Algorithm

Hearing aids already have features that make it less difficult to hear in noisy settings. But now that we understand what the fundamental process looks like, hearing aid makers can incorporate more of those natural functions into their instrument algorithms. For example, you will have a greater ability to hear and comprehend what your coworkers are talking about with hearing aids that assist the Heshl’s gyrus and do a little more to differentiate voices.

The more we learn about how the brain works, specifically in conjunction with the ears, the better new technology will be able to mimic what happens in nature. And better hearing outcomes will be the result. That way, you can focus a little less on straining to hear and a little more on enjoying yourself.

Why wait? You don't have to live with hearing loss. Call Us Today