Audio Problem: Unable to hear voice in local speaker

Checklists:

1. Check that the correct device is being used.
2. Check that no other application is using the devices. It is common to not be able to use sound device when other application is using the device.
3. Check that speaker is functioning properly by Looping-back Microphone to Speaker device.
4. You can also check by Playing a WAV File to Speaker.
5. Check that Incoming RTP Packets are Indeed Received by Local Host
6. Getting Around NAT
7. Check that the Call is Connected to the Sound Device in the Conference Bridge.
8. Check that CPU Utilization is not Too High