Random object materials sound like walking on metal

In most maps I load, whether in singleplayer or multiplayer, dirt will sound like metal (when you walk on it) most of the time, and stone and wood textures will sound like metal aswell, does anyone else have this problem, and how do I fix it?

I apologize for the bump but I too have the same problem as well, and it’s getting quite annoying because it ruins my immersion~

Have you tried to verify integrity of game cache for HL2 and GMOD? If you did, then one of the custom files in the garrysmod folder could be causing this.