Electrical, electronic, electroacoustic instruments and parts thereof for receiving, transmitting and reproducing audio signals, namely, microphones, filters for noise reduction, mains receivers, electroacoustic transducers, headphones, loudspeakers, stereo amplifiers, batteries, battery chargers, and parts thereof; equipment for broadcasting, transmitting and receiving sound or video signals, namely, stereo receivers, audio receivers, stereo amplifiers, stereo tuners; high-frequency sound transmission equipment and sound transmission engineering equipment, namely, pocket transmitters and pocket receivers; devices for wireless transmission of acoustic information, namely, wireless microphone receivers, diversity receivers, stereo receivers; antennas; assitive listening devices not for medical use, namely, hearing amplifiers, infra-red transmitters and receivers; instruments for communications engineering, namely, communication headsets and headphones for use in conferences and simultaneous translations, all areas of telecommunications, airlines and air traffic control, news reporting, military communications, the aforementioned with and without active noise compensation; soundproofing devices, in particular in headset form; devices for recording and reproducing electrical signals, namely, audio signals; computer hardware; coaxial cables, computer cables, electrical cables, fiber optic cables; computer software for controlling, tuning, monitoring and demonstrating signals transmissions on disks, CD-ROMS, data cartridges, tapes