Electrical, electronic, signal and monitoring apparatus and apparatus for receiving, transmitting and reproducing electrical signals and parts therefor, namely, [ radio, television and satellite transmitters, ] high-frequency receivers, and high-frequency input modules; [ apparatus for recording and reproducing electrical sound signals, namely, digital and audio tape recorders; ] apparatus for wireless transmission of acoustic information, namely, wireless microphone transmitters and plug-in microphone receivers; [ software and data media programmed for use in the transmission and reception of signals in the form of diskettes, tapes and disks; electroacoustic and visual identifiable guide systems composed of sound signal receivers, audio transmitters and headphones for providing verbal information in single- or multiple-language format for use in museums, exhibitions, theaters and other public events; ] apparatus for [ broadcasting, ] transmitting, and receiving sound signals and video signals, namely, high-frequency sound-transmission apparatus and sound-transmission engineering apparatus, namely, pocket radio transmitters and pocket audio receivers for UHF and VHF ranges and parts therefor; diversity audio receivers and small audio receivers; [ live news coverage apparatus, namely, broadband radio transmitters with command audio receivers, backward channel radio receivers, backward channel radio transmitters, diversity program audio receivers, and command radio transmitters; antennas; ] apparatus for narrow-band and broadband systems in sound-transmission engineering; radio transmitters, pocket radio transmitters, and pocket audio receivers; multichannel radio transmitters, single-channel radio transmitters and infrared radio transmitters; multichannel, single-channel and two-channel audio receivers, headphone audio receivers, chin-strap audio receivers, and parts therefor; apparatus for sound transmission and sound reproduction, namely, infrared and high-frequency audio transmitters and audio mono-receivers, stereo audio receivers, two-channel audio receivers, and chin-strap audio receivers; [ connectors for listening and speaking devices, namely, adapters; ] instruments for communications engineering systems, namely, communication headsets and headphones for use in conferences and simultaneous translations in all areas of telecommunications, [ airlines and air traffic control, ] news reporting, [ and military communications; ] microphones, namely, dynamic microphones, condenser microphones, soloist microphones, pressure microphones, switchable microphones, interface microphones, electret microphones, headset microphones, goose-neck microphones, directional-tube microphones, wireless microphones, and clip-on microphones; microphone parts, namely, microphone diaphragmatic capsules, omnidirectional foil electret capsules, microphone modules effected through computer-aided acoustic design and laser interferometry techniques, microphone terminal distributors, and microphone sleeves for protection of wind, sweat, and spit; microphone sleeves and parts thereof; electroacoustic transducers with infrared transmission or high-frequency transmission, namely, headphones, dynamic headphones, electrostatic headphones, wireless headphones, [ and headphones for use in aircraft, buses and trains; ]headphones and headsets with and without active noise compensation; parts and accessories for electroacoustic transducers and headphones, namely, ear pads, [ volume controls, high-end and tube amplifiers, batteries, battery chargers and cable connectors; computer software for controlling, tuning, and monitoring the foregoing products ]