Megaphones; Metronomes; Microphones; Radios; Acoustic conduits; Audio mixers; Audio- and video-receivers; Cabinets for loudspeakers; Earpieces for remote communication; Integrated circuits; Radio pagers; Recording devices for sound and image carriers; Sound transmitting apparatus; Stands adapted for laptops; Tone arms for record players; Vacuum tubes for radios; Video projectors; Wah-wah pedals