Thanks for reply, i couldn't get it to work depsite your instructions however, i got it to work the other way, i took sentences i want from VOX folder, put them together in audacity, and exported them in right format, added into my mod and placed as ambient generic that gets triggered when i walk past certain point.
I hope everyone who was wondering how to do it aswell, now will know, also tutorials how to add sounds into HL can be found easily.