Rain Traffic Sound Oddity

Okay, this is surely a very weird thing to blog about, but I was curious if anyone else had noticed this.

Has anyone else ever noticed that when it's rainy outside—and it doesn't even necessarily have to be pouring... it can just even be drizzling or even just muggy—distant traffic noises outside sound louder than usual? Like motors and engines sound louder. There's a freeway about half a mile away from our house, and whenever it's rainy, drizzle-y, or muggy outside, I don't know... it always just seems louder. And it's not like it's the tires on the wet roads that I'm hearing.... unless I am.... but it doesn't sound like tires. It sounds like the motors/engines.

Maybe it's because rain water is splashing up into the engines and making them work overtime? Maybe it's a trick of the ear? Like how the moon looks bigger on the horizon, except it's actually the same size as it is when it's up in the sky? You know how that moon trick can trick your ear? It do. So just watch out.