General tips:

• Are your speakers and microphone plugged in to the right sockets and turned on?
• Test your audio by pressing the TALK button with your mouse or holding down the CTRL key, you should see the microphone audio meter bar light up green
• Are the Microphone or Speaker icons in your Local AV Audio menu Red/Muted? Click to unmute them.
• Has the sound ever worked outside of iVisit?
• Are updated Sound Card drivers installed?
• Are the Sound Card and Microphone selected in the iVisit Preferences?
• Are other audio programs disabled? (PC NetMeeting, MSN, Yahoo! Messenger, Music players?)

For PC specific audio issues click here
For Mac specific audio issues click here