If you are interrested into getting "double/multi/mega/ultra kill"'s sounds on Blockade 3D (Steam): then run this script.
Install AutoHotkey available at https://autohotkey.com/
Run the killstreak-sounds-blockade_classic_v*.ahk
Please follow instructions in the displayed message.
Restart if you did not meet the requirements on the first start.
Enjoy.
On Blockade Classic:
On Blockade 3D (before global update)
https://www.youtube.com/watch?v=wsqemdEPgCA
Please read the TODO.md