Physical, acoustic, optical, electro-technical, signaling, measuring, monitoring, photographic, cinematographic, radio, and electroacoustic apparatus, namely, microphones, headphones, loudspeakers, electroacoustic transducers, sound reverberation units, amplifiers, structural parts for the above; loudspeakers; voice machines, namely, electroacoustic transducers, reproducing headphones, and structural parts for the above; microphones, headphones, loudspeakers, electroacoustic transducers, amplifiers, and structural parts for all of the aforesaid goods; wireless headphones; electronic transmitter stations for wireless headphones; intercom comprised of microphone and headphone; amplifiers; acoustic pick up, recording, transmission and reproduction apparatus, namely, microphones; reverberation and delay apparatus, namely, sound reverberation units, in ear monitors not for medical purposes, wireless microphones; infrared sending apparatus, namely, infrared microphone and headphone transmitters, infrared receivers for microphones and headphones, infrared battery chargers for microphones and headphones, wireless microphones; handheld microphone and headphone transmitter; pocket microphone and headphone transmitter; stationary receivers for microphones and headphones; pocket receivers for microphones and headphones; battery chargers for microphones and headphone; in-ear monitors not for medical purposes; wireless headphones and receivers for audio and video signals; [ transmission and receiving apparatus and installations, namely, ultrasound converters; ] accessories for ultrasound converters, namely, ultrasonic electroacoustic transducer units; [ studio apparatus, namely, vibration meters; ] acoustic positioning, locating and distance measuring apparatus, namely, frequency scanners for wireless frequency; measuring apparatus as well as complete measuring stations for acoustic testing, namely, electroacoustic transducers, amplifiers, and structural parts for the above; sound frequency generators; stereophonic apparatus, namely, ultrasonic electroacoustic transducer units; projection apparatus, namely, headphones, loudspeakers and electroacoustic transducers; [ projection screens; ] stereo and color film apparatus and components and accessories therefor, namely, headphones, loudspeakers, electroacoustic transducers, reproducing headphones, amplifiers, and structural parts for the above; acoustic component parts, namely, microphones, electroacoustic transducers, transformers for sound recording and reproduction, transformers with built-in amplifiers and voice controls; replacement structural parts for the aforesaid goods, individual structural parts for the aforesaid goods