Echoes in the room are caused by sound reflections off smooth surfaces such as hard walls, floors, and ceilings. The shape of the room, the floor, ceiling, and walls all affect reflection. An acoustically treated room will not have echoes. To reduce echoes, acoustical ceiling tile and wall covering should be considered. Television does not add to acousti-cal difficulties already existing in a room, but it does make them more acute.
Most interactive classrooms have three cameras.
Remote tilting and panning can also be added as extra features. Monitors let the instructor and origination site students view students at the remote site. Monitors also let the instructor view what is being transmitted. Monitors at the remote site show what is being transmitted from the origination site. Some systems use a split screen to present the view from two cameras.