Sound recording apparatus; sound transmitting apparatus; sound reproduction apparatus; sound processing apparatus, namely, digital sound processors; sound mixing apparatus, namely, sound mixers; video recorders; camcorders; electric and electronic effects units for musical instruments; digital sound processors; analogue sound modifiers, namely, sound effect pedals for musical instruments; audio interfaces; audio and video receivers; audio equalizers; data processing apparatus; transponders; megaphones; loudspeakers; monitoring apparatus and instruments, namely, electric monitoring devices for monitoring sounds not for medical purposes; headphones; sound amplifiers; amplifiers for musical instruments; audio mixers; audio mixing consoles; illumination regulators, namely, stage lighting regulators; microphones; acoustic couplers