9 Electric, optical signaling and checking apparatus and instruments, namely signal distribution system with built-in audio router comprising a digital matrix based on timeslots with a plurality of analogue and digital input and output boards; apparatus for recording, transmission and reproduction of sound and images, namely monitors, CD players, DAT recorders, effects processors; installations for acoustic irradiation and for alerting composed of central unit, microphone speaker stations, relay-module, final amplifiers and loudspeaker control modules; sound transmitting devices for sound and film studios, namely audio mixing consoles, monitors, CD players, DAT recorders, effects processors; acoustic couplers, electric couplings, electricity indicators, sound recording apparatus, namely mixing consoles; computer operating programs; computer software for use to control of proprietary PC-based products, interface for user-friendly programming of scenarios, sequences, and control commands in the field of audio, video and broadcast technology; electronic notice boards; audio and video receivers; remote control apparatus, namely serial remote control device operating over RS232, RS422 or RS485 interface ports, for control of external devices, audio sources, effects processors, amplifiers; tape recorders; speed regulators for tape recorders; high frequency apparatus, namely wireless microphone signal transmission-Microport; interfaces analog/digital and digital analog converters; electric regulating apparatus, namely monitoring modules for amplifiers and speakers; loudspeakers; microphones; video monitors; video recorders; switchboards; electric apparatus for commutation, namely relay boxes for controlling external units; distributing consoles; sound recording, locating and transmitting apparatus, namely metering units and signal routers; amplifiers; sound reproduction apparatus, namely players and DAT recorders; systems for calling and intercommunication composed of a central unit, microphone speaker stations with intercommunication function, relay-modules and final amplifiers; systems for transmission and distribution of audio and video signals composed of basic units with audio-input modules video-input modules, video-output modules data interfaces and light-wave transmission cards; installations for the controlling of performances composed of central unit, microphone speaker stations, relay-modules, final amplifiers, loudspeaker control modules and stage manager desks; systems for transmitting and distributing of binary switching signals for universally using in buildings composed of basic units with binary input modules, binary output modules, data-interfaces and bier transmission cards; controllers and dimmers for stage lighting; software for streaming of audio and video material on the Internet