If you cannot hear the presenter during a webinar, click the "Audio" menu at the top of the screen, then "Integrated VoIP", and finally "Join Conference".

If you are not viewing the main WebEx screen where this menu is located, then you will need to click the "Return to Meeting WIndow" button (see image below), then do the instructions above.

If you encounter an error message, such as "you do not have the necessary audio capability", please call WebEx technical support at 866-229-3239.