Why Can’t I Hear in a Crowd?

Man can't hear in a crowded restaurant.

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 meant that you paid attention to the part about going to the fair and (maybe intentionally) ignored the part about cleaning your room.

But actually selective hearing is quite the ability, an impressive linguistic task carried out by cooperation between your ears and brain.

The Difficulty Of Trying to Hear in a Crowd

Maybe you’ve experienced this situation before: you’ve been through a long day at work, but your friends all insist on going out to dinner. They choose the noisiest restaurant (because it’s trendy and the deep-fried cauliflower is the best in town). And you strain and struggle to follow the conversation for the entire evening.

But it’s difficult, and it’s taxing. And it’s a sign of hearing loss.

You think, maybe the restaurant was simply too loud. But… everyone else seemed to be having a great time. You seemed like the only one having trouble. Which makes you think: Why do ears with hearing impairment have such a difficult time with the noise of a packed room? Just why is it that being able to hear in a crowd is so challenging? Scientists have begun to discover the solution, and it all starts with selective hearing.

Selective Hearing – How Does it Work?

The phrase “selective hearing” is a process that doesn’t even take place in the ears and is formally known as “hierarchical encoding”. This process almost exclusively occurs in your brain. At least, that’s in line with a new study carried out by a team from Columbia University.

Scientists have recognized for some time that human ears basically work like a funnel: they collect all the impulses and then deliver the raw information to your brain. That’s where the heavy lifting occurs, specifically the auditory cortex. Vibrations caused by moving air are translated by this portion of the brain into recognizable sound information.

Because of substantial research with CT and MRI scans, scientists have recognized for years that the auditory cortex plays a crucial role in hearing, but they were clueless with regards to what those processes actually look like. Thanks to some unique research methods concerning participants with epilepsy, scientists at Columbia were able to learn more about how the auditory cortex functions in terms of picking out voices in a crowd.

The Hierarchy of Hearing

And the insight they discovered follows: the majority of the work accomplished by the auditory cortex to pick out distinct voices is done by two separate regions. They’re what allows you to separate and enhance distinct voices in noisy settings.

  • Heschl’s gyrus (HG): The first sorting stage is taken care of by this part of the auditory cortex. Heschl’s gyrus or HG breaks down each unique voice and separates them into distinct identities.
  • Superior temporal gyrus (STG): The differentiated voices go from the HG to the STG, and it’s here that your brain begins to make some value distinctions. Which voices can be comfortably moved to the background and which ones you want to pay attention to is figured out by the STG..

When you have hearing impairment, your ears are lacking certain wavelengths so it’s harder for your brain to differentiate 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 information. It all blurs together as a result (which makes interactions difficult to follow).

New Science = New Algorithm

It’s standard for hearing aids to have functions that make it less difficult to hear in a crowd. But hearing aid manufacturers can now include more of those natural functions into their algorithms because they have a better idea of what the process looks like. For instance, you will have a greater ability 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 differentiate voices.

The more we understand about how the brain works, especially in conjunction with the ears, the better new technology will be capable of mimicking what happens in nature. And better hearing outcomes will be the result. That way, you can concentrate a little less on straining to hear and a little more on enjoying yourself.

The site information is for educational and informational purposes only and does not constitute medical advice. To receive personalized advice or treatment, schedule an appointment.