There is no sound in the smart classroom.
There are a couple of causes for this. First ensure that the sound on the machine has not been muted. If that checks out then you need to check the back of the computer to see if the audio jack has been pulled loose from the computer. Some instructors plug in pen drives to the back of the machines and sometimes pull them out too far, disconnecting the audio in the process. If that also checks out and there is no sound, contact the callcenter (ext. 3333) for further assistance.