audio amplifiers; wireless receivers; megaphones; microphones; audio key controllers; sound speakers; audio cassette tape players and recorders; audio 8-track tape players and recorders; radio tuners and receivers; audio mixer; chimes (in the nature of electric note generators for the purpose of indicating that an announcement is forthcoming); voice adapters; horns (loudspeakers) and driver units for horns; reflex horn speakers; public address systems comprising one or more of the components ...