Sorry for noticing your post so late.
Did the sounds play without any problem on your local server?
If so, you have correctly installed the downloaded pk3.

One thing you notice is that you can't make it work on the server with "sv_pure 0"
You can check the server config by typing "configstrings" in console -> scrolling up to the index of "1: " -> going through the strings until you find "\sv_pure\0" or "\sv_pure\1"

Hi, this sounds very interesting.

I'm not able to make it work, would you please be so kind as to help?

Thank you.