More Cave Sounds — FAQ

Compatibility

Texture packs - no conflict at all, since nothing visual is overridden. Order in the pack list does not matter.
Shaders - unaffected; shaders do not touch sound.
Other sound packs - only packs that also replace the cave ambience event can conflict. If two such packs are active, whichever sits higher in the selected list wins.
Servers - the pack is client side, so you hear the extra sounds on any server without the server needing anything.

It makes no gameplay changes and has no measurable performance cost.

The new clips are deliberately written to sound like the originals: low, distant and hollow, at the same volume, so nothing jumps out as obviously added.
Ambience is random and fairly rare by design, so give it a few minutes underground before judging how much has changed.
Safe to add to or remove from any world at any time - no world data is involved.
If you hear nothing at all, check that the Ambient/Environment volume slider is not turned down.