Problem changing Half Life: Source sound files

[mista_bojjob]

So I'm trying to change the enemy sounds in half life: source to TF2 voices, just as a joke kinda thing...
so far I've only done the headcrab sounds but the trouble is... the alert, idle, death and pain sounds don't play. Only the jump and headbite sounds work.

The weird thing is... When you see the first scientist get dragged into the airvent and gibbed, it plays the headcrab pain sound files i set perfectly, so i have no idea what's wrong with them.

can anyone tell me what's wrong and how i can fix it?

[tschumann]

Are you getting any errors in the console?

[mista_bojjob]

nope

[superdinoman]

Proper length?
Proper file settings?
Proper file type?

[mista_bojjob]

superdinoman, that doesn't seem to make much difference since i've got other sounds that are different lengths and they still work

and Wormy, they're all in .wav anyway XD