Where Do I go to turn it on public in game... Just wondering???

i dont know i have it on but i still cant hear people but if you go to other game types and look for VOIP with it on (old school) you can hear people but other the that i have know idea why they wont just let people talk to each other. . . .or join a fire team and you can talk

OK.... whats the default talk button???

In your autoexec.cfg insert the following lines:

s_volume_voipin_db 0
s_volume_voipout_db 0

You can also type these into the console.