This isn't probably the best place for this question. Maybe Teaching Strategies or even Open Social Forum?
First, in what way do you want to interact with voice and video? One on One, One to Many, Many to Many? Are you thinking of using video lessons? Using some kind of Video Conferencing, Voice Chats?
There are many questions to be answer before anyone can give you an aswer.
If you could give a little more info someone might be able to guide you in the right direction.