Computer hardware and software for signal processing, audio and visual mixing, synthesising, and recording, sound reinforcing, audio processing, virtual reality processing, fast fourier transform processing (FFT processing), auralization processing, and frequency domain processing; signal processors; audio and visual mixers, synthesisers, and recorders; sound reinforcers; audio processors; virtual reality processors; fast fourier transform processors (FFT processors); auralization processors; frequency domain processors; and user manuals for use therewith sold as a unit