Why mud tires get noisier with higher miles?

[WranglerGuy]

Have you ever noticed that as mud tires pick up miles, that they get louder? Why is that? Is there a way to shave down the high points on the tires to cut down road noise?

 

[TRX Tim]

That's how it is mate, personally I don't mind it. What tires are they? Have they gotten too loud for you?

 

[M Kesik]

It happens around 15k I've noticed. How many miles you have on those tires. It's the 9th mystery of life. Who knows.