Audio speakers; audio players; audio apparatus; audio recordings; audio timers; audio amplifiers; audio digitisers; audio cable; audio discs; audiovisual receivers; audiovisual instruments; audiovisual apparatus; audio-video receivers; audio dubbing apparatus; audio mixing consoles; audio mixing desks; audio testing apparatus; audio transmitter units; audio frequency apparatus; audio cassette players; audio recording apparatus; audio mixing apparatus; tape head cleaners; audio speaker enclosures; audio cable connectors; audio switching apparatus; audio processing apparatus; integrated audio amplifiers; audio circuit boards; speakers [audio equipment]; audio conference apparatus; audio digital discs; audio compact discs; car audio apparatus; audio electronic apparatus; digital audio tapes; audio tape recorders; audio visual recordings; receivers (audio-- and video- -); audio speakers for home; audio speakers for automobiles; discs (compact -) [audio-video]; high fidelity audio apparatus; audio- and video-receivers; compact discs [audio-video]; signal processors for audio speakers; audio devices and radio receivers; audio/visual and photographic devices; software to control and improve audio equipment sound quality; electronic audio signal processors for compensating sound distortion in speakers; power units (batteries) connected to audio apparatus for use in motor vehicles; computer software to enhance the audio-visual capabilities of multimedia applications; instruments for the reduction of noise in systems for recording audio signals