We’re having a lively back-and-forth conversation when the train flies by overhead. Immediately, the space between the brick walls is steeped in violent soundwaves, washing away his words before they hit my ears. I strain to hear him amid the roaring and rattling of the Red Line on its grinding old tracks, the honking and screeching of cars on the street and the ordinary sounds of city.

When the train finally passes and sound returns to baseline, his voice sounds sharper than usual. He continues speaking and I hear him, but I grasp for understanding like a person blinded by the flash of a camera. He asks me if I heard him, and though I’m still fishing for a full picture of what it was he said, I reply that yes, I did.

As the world becomes increasingly industrial, the calm sonic environments in which we evolved shrink. I grew up in a remote rural town where the loudest sounds in the night are the occasional howling of a coyote and the hooting of an owl. I relocated to Chicago when I was 18 and was frequently overwhelmed, unable to sleep, with the constant whirling of sirens and pulsing of elevators in my building. Things are a little better away from the city center, but four years later, I still struggle to process information when there are multiple loud sound stimuli.

This may be because I was raised in such quiet areas. New research published in the Proceedings of the National Academy of Sciences has shed some light on how the brain changes itself in environments of shifting noise levels.

Hearing requires that our ears send information to our brains via neurotransmitters, a chemicals that tells the neurons of the brain how to react. When there is more sound in the environment, the nerves tell the neurons to release more neurotransmitter to emphasize the amount of sound. However, the brain can only produce so much neurotransmitter fluid, so if there is excessive sound, we can only process so much at once. We essentially run out of gas and simply give up on processing sonic information.

Researchers from the University of Buffalo and from the Johns Hopkins University School of Medicine exposed mice to varying types of noise stimulation, ranging from the loudness of a lawn mower to a hair dryer, and measured how their brains reacted. They observed an interesting phenomenon: Over time, as the mice were more regularly exposed to loud sound, their brains adapted and began to be more frugal with neurotransmitter chemicals. Less meant more, so they were able to adjust their sound baseline to more loud sounds in the environment.

The same worked in reverse. The mice were able to readjust to quieter environments after they were not regularly exposed to the same loud sounds anymore, showing the elasticity of the brain.

While not exactly revolutionary—the concept of slow adaptation is hardly novel—the application could be fairly widespread. Sound is something that’s hard to control and predict, and the constant introduction of new, loud devices can have devastating effects on one of the most crucial senses.

For example, a study conducted in the late 1980s examined deafness among young Eskimo men in Greenland. Curiously, men under 25 were going deaf at prodigious rates while the older men were not. After some context and examination, the young men’s deafness was linked to their rifle use. In a quiet, snowy environment like Greenland, the sudden burst of a rifle for hunting could have a massive leap in decibels hitting the young men’s ears. Their brains were unable to cope and the nerves were damaged, resulting in years of hearing damage with each shot.

Sonic environments are a little-considered part of city planning and life planning, but perhaps they should be considered more often. Lord knows that soundscapes are hardly something you can map into a price range for a house, but anyone who has hunted for apartments has seen the word “quiet streets.” Evolution attracts us to quiet areas, where we can easily hear predators and threats to our families. However, as the UB and Johns Hopkins researchers have shown, our brains seem to be able to adapt.

I wonder why mine still has trouble.