loudspeakers; loudspeaker drivers; stereo speakers; computer speakers; amplifiers; microphones; tuners; mixers used in sound production and amplification; automobile radios and radio tape deck combinations; automobile radio speakers; automobile radio speaker systems; am/fm converters; graphic equalizers; power boosters; rheostat switches; fader controls; wiring; mountings for automobile audio equipment; speaker grills; citizens' band transceivers; antennas; cassette players, compact disc players; compact disc adaptors; cassette adaptors; noise filters; radio knob sets; fm antenna signal boosters; head cleaner cassettes; plastic housings for car radios and car radio speakers; plastic grills for car radios and speakers; electrically operated sound amplification and sound amplification and reproducing systems, namely, public announcement apparatus and the structural components thereof; electronic controls for automatically adjusting the audio level of a sound system to compensate for variations in ambient noise level; apparatus and parts thereof for the synchronous production and reproduction of audio or video reinforcement; computer software used in the field of acoustic planning and/or design, and accompanying instruction manuals sold as a unit; computer software used in the field of loudspeaker system design, and accompanying instruction manuals sold as a unit; digital signal processors; computer software for digital signal processing; sound processors and playback apparatus; digital audio recording and playback telephones; telephones; speaker phones; electronic hardware and computer software used in control of loudspeakers, mixers, amplifiers, and related audio products; computer peripherals for desktop personal computers, laptop computers and personal digital assistants; remote control for a personal computer; audio apparatus for audio input and output to/from a computer; speaker headsets; wireless headset systems comprising a speaker headset having a wireless receiver and a base unit having a wireless transmitter; headsets comprising speaker and microphone; wireless headset system comprising a headset having a speaker, microphone and wireless transmitter and receiver, and a base unit having a wireless transmitter and receiver; dual pick-up microphones; microphones capable of automatically localizing sound; microphones having noise cancellation features; microphone systems comprising a dual pick-up microphone and computer software for use in localizing and/or noise cancellation; audio signal enhancing computer software or hardware; signal enhancing computer software or hardware for enhancing the voice portion of an audio signal; voice enhancing algorithms; apparatus for use in connection with the processing, recording, reproduction, transmission and reception of electronic signals; integrated circuits; test apparatus for testing and troubleshooting for processing, recording, reproduction, transmission and reception of electronic signals