If you think you may need assistance, one resource is AV Event Support, a service to help meet the audio and video needs of instructors, researchers, and administrators by providing fee-based AV support tailored to their requirements.

Audio Hardware

You'll need audio hardware appropriate to the location. Typically, attempting to use a laptop’s built-in microphone and speakers for the audio in a conference room will not yield good results. You'll likely need to connect external audio devices appropriate to the size and acoustics of the room. 

Only One Audio Connection Per Location

If part of your session is taking place in a room where multiple people will be present, you should only have one audio connection. In other words, if you already have a device connected to the session audio conference, make sure that anyone else (in the same location) who wants to join the session only connects to the video component and does not join the audio conference. Having multiple audio sessions open in the same place often results in echo or feedback loops.