Ever wonder why a train horn or barking dog sounds louder on a crisp winter morning? Turns out, it's not just your imagination — there's real science behind it.

The weather culprit

In the winter, we often see warmer air set up above a pocket of cooler air near the surface, as shown in the image below. This is called a temperature inversion.

This is the opposite of what we typically see in the summer where the sun heats up the ground, creating a layer of warmer air near the surface with cooler air above.

And it makes all the difference in what your ears can hear.

(MORE: Here's when fall's first freeze arrives in your town)

Now, add in the sound waves

The key is that sound waves travel faster in warmer air than in cooler air.

Get More of Our News on Google

Set The Weather Company as a 'Preferred Source' to get quicker access to the news you value.

When warmer air sets up above cooler air, the contrast between the two causes the sound waves to bend down toward the ground, closer to your ears.

Meanwhile, if the temperature layers were flipped — like we often see in the summer — the sound waves would bend upward, moving farther away.

This is why noises like train horns, dogs barking, traffic and talking carry farther and sound louder to you during the winter.

(MORE: When to expect the first accumulating snowfall of the season)

The snowy exception

One winter phenomenon can put a damper on your seemingly supersonic hearing: snow.

The most common type of snowflake, known as a dendrite, has six "arms" that extend out from the center.

As these flakes fall toward the ground, they capture the sound waves in the spaces between their arms, muffling the sound before it reaches your ears.

(MORE: Why falling snow makes it quieter outside)

Once a whole fresh layer has fallen, the snow-covered ground acts similarly to padding in an audio booth, absorbing the sound rather than allowing it to bounce around.

But this snow-induced silence doesn't last long.

As the snow begins to melt and refreeze, the dendrites lose their distinctive shape that captures the noise. This means old snowpack does not dampen sound like the freshly fallen stuff.

Caitlin Kaiser graduated from the Georgia Institute of Technology with both an undergraduate and graduate degree in Earth and Atmospheric Sciences before starting her career as a digital meteorologist with weather.com.