Apparatus and instruments for checking, supervision, monitoring, and viewing sound and images, namely, video-audio enhancers, color processors, signal switchers, signal distributors, radio frequency (RF) processors, special effects generators, video encoders and decoders, video standard converters, video time base correctors, computer generator locking equipment namely, generator locking device for graphics and text overlay, computer-controlled video equipment, namely, video matrix and processing control, computer interface products, namely, TTL (transistor-transistor logic) analogue encoders, TTL (transistor-transistor logic) to analogue converters, TTL (transistor-transistor logic) audio visual signal distributors, TTL (transistor-transistor logic) generator locking encoder cards, audio signal defect correctors, video line amplifiers, video screen splitters, video time base signal delay correctors, blank magnetic data carriers; apparatus and instruments for recording, transmission, processing or reproduction of sound and images; apparatus and instruments for controlling and transmitting video, audio and communication signals and information via wires or wireless means, namely, video-audio signal distributors, video-audio signal switchers and matrix switchers, video and audio enhancers, video and audio processors, radio frequency (RF) processors, special effects generators, video encoders and decoders, electronic video signal scalers; scan converters; video standard converters; video time base correctors; computer generator locking equipment, namely, genlock (generator locking) device for graphics and text overlay; computer controlled video equipment, namely, video matrix and processing control panels; computer interface products, namely, TTL (transistor-transistor logic) analogue encoders, TTL (transistor-transistor logic) to analogue converters, TTL (transistor-transistor logic) generator locking encoder cards; room control devices, namely, electric switch wall plates and table bus bars with infra-red, ethernet, wireless network and controlling devices; audio signal defect correctors; video line amplifiers; twisted pair signal transmitters and receivers; video screen splitters and video time base signal delay correctors; electrical cables and wires; amplifiers; microphones; loudspeakers; centrally-controlled audio-video system comprised of audio amplification providing solutions for the integration of media and control in classrooms, training rooms and presentation rooms, comprising wall or ceiling-mounted multi-media projectors, wall or ceiling audio speakers, computer software for graphics videos, computer hardware for playing graphics videos, display screens, and optionally, DVD players; display screens; furniture-mounted connection bus featuring a power source, universal power sockets, video, audio, telephone and other network connectors; computer operating software for the aforementioned products; parts and fittings for the aforementioned products; furniture-mounted connection buses featuring a power source, universal power sockets, active or passive video, audio, telephone and other network connectors; parts and fittings thereof; controlled audio and video apparatus and fittings therefor, namely, electric, electronic, matrix and video-audio signal switches, audio and video processors, microphones, loudspeakers and display screens for producing and selectively transmitting audio and video in enclosed spaces; software for controlling audio, video and projecting accessories and computers in classrooms, boardrooms, conference rooms and auditoriums, enabling selective connection of input sources of audio and video signals, such as laptops and DVD's, for providing an interface and facilitating connection and controlled display of a plurality of such sources