Whenever I put out an ambient generic and then go into the sound list and press wheatleys or Glados voice sound they dont play. But they do in game. Anyone knows how to fix this?

They're not normal sound files per se, they're scenes. You need to use a logic_choreographed_scene, then it will work even better.

I think what the OP meant was that the sounds won't play in the sound browser. That is a common problem, and unfortunately as far as I know, not fixable. You can though get GCFScape and open pak01_dir.vpk. That should have the sound files in it for preview. Another (easier) option is to go here: http://theportalwiki.com/wiki/Wheatley_voice_lines. There's other pages for the different characters there. Click on a line you'd like to use, and in the URL there'll be the sound name (for example, Wheatley_openingbraindamageapplenag01) That's what you'll filter for in the sound browser to find either your voice file or scene.
Also, ambient_generics (in my experience) work just fine as voice lines so long as you don't need characters interrupting, or animations of any sort. But yeah, logic_choreographed_scene is a lot less kludgey.

Thanks you guys. That really helped alot

i got a question to add to this. is it in any way possible to make the scene or actors play the sounds everywhere in an ambient_generic does? I have large rooms where the player should be able to hear characters talk on the other side of the room but it sounds weird when you walk past the actor, towards the character

All scenes use raw sounds, therefore you could use an ambient_generic to play them.

I tried that once, they played at nonstop and incremented speed uncontrollabley