Abstract: In a noise enhancement system for use in a vehicle having an engine, a memory contains stored data representing desired sound relating to vehicle speed or the engine speed. The system is provided with a source of first signals indicative of the vehicle speed or the engine speed and a generator to generate vehicle engine noise desired by an occupant of a cabin of the vehicle. The generator includes a synthesizer to synthesize desired vehicle engine noise signals used to generate the desired vehicle engine noise and a microprocessor responsive to the first signals to use appropriate data of the stored data in dependence upon the vehicle speed or the engine speed indicated by the first signal to control the synthesizer to synthesize the desired engine noise in time with the vehicle speed or the engine speed indicated by the first signals.