why I can not talk on sl nor hear the others talk

[Patricia Ball]

I followed all the direction on sl but still can't talk 

[Peewee Musytari]

Do you see a white dot over your head and over the heads of other people around you that have voice switch on?

Do you see green lines radiating from the dot when you speak into your mic?

If the answer is yes, check your headset or speakers and volume levels.

If you don`t see the white dots, then either voice is not enabled or you are on land that does not allow voice.

Grab a friend that has voice working and both go to Voice Echo Canyon that is the best place to test it because you can hear yourself speaking when it is working correctly.

http://community.secondlife.com/t5/English-Knowledge-Base/Voice-chat-FAQ/ta-p/700171