java_programmer 0 Junior Poster

I am using Ubuntu 11.04 and using Empathy as chat client.
I have added my gmail and yahoo account in the Empathy and they are working fine.
I can now chat with friedns without any problem. But when I am trying to voice chat, I can't hear from friends but they can hear me. I checked my audio device and driver and my headphone. All these are working fine with other application like watching movie, listening music etc. But not working with Empathy client. Do we need other configuration?
Please help.