If you did not receive a direct URL from a presenter or host:
Meeting hosts have control over how the audio portion of your meeting is conducted. Depending on how the meeting host set up the meeting, depends on how you will respond. You can hear meeting audio through your computer speakers or headset. If a meeting attendee is speaking, you will see a microphone icon next to their name within the attendee roster.
If the host set up the microphone rights for all participants, anyone can respond verbally, using their headset and microphone. In some cases, meeting hosts may give you the ability to speak. When this is the case, a dialog will alert you that you have the rights to use your microphone. Clicking the Speak Now link will activate microphone icon in the Application Bar at the top of your screen.
If you are having issues with using VoIP, it is recommended that you run through the audio Setup Wizard to optimize your experience. To do this, select Audio Setup Wizard from the Meeting menu.
Within a meeting, you can also change your status to provide feedback to the presenter and other attendees.