depmod has nothing to do with sound. depmod just figures out how your
modules depend on other modules. You still need to load the sound
modules in order for them to be useful.
There have been MANY threads about getting sound to work, I would
suggest you browse through those first as it's very likely someone else
has had the same problem you're having.
To begin (as root) do a:
If you don't see your sound modules loaded, you need to load those.
For help on the module control programs: