Abstract: A sound bypass device configured to transmit engine-generated sound pulses from an engine to an auditory environment whilst preventing the flow of gases to the auditory environment, the sound bypass device comprising: a chamber enclosing an internal volume between an inlet of the chamber and an outlet of the chamber, the inlet of the chamber being configured to receive gases exiting or entering the engine of the vehicle and the outlet of the chamber being configured to transmit sound pulses to the auditory environment; a first flexible membrane located within the chamber, the first flexible membrane being configured to transmit engine-generated sound pulses from the gases whilst preventing the movement of gases from the inlet of the chamber to the outlet of the chamber; a second flexible membrane that is separated from the first flexible membrane within the chamber; and a hollow spacer coupled to the first flexible membrane at a first end of the spacer and to the second flexible membrane at a second end of th

Abstract: A sound bypass device configured to transmit engine-generated sound pulses from an engine to a sound outlet whilst preventing flow of gases to the sound outlet, the sound bypass device comprising: an input tube configured to conduct the engine-generated sound pulses from the engine; and a sound transmission device connected to the input tube at a first end and to the sound outlet at a second end, the sound transmission device comprising: a first volume connected to the first end, a second volume connected to the second end, and a flexible diaphragm separating the first volume from the second volume and configured to transfer variations in pressure in the first volume to the second volume; wherein the first volume has a cross-sectional area that is greater at the diaphragm than at the first end and the second volume has a cross-sectional area that is greater at the diaphragm than at the second end.

Abstract: A sound bypass device configured to transmit engine-generated sound pulses from an engine of a vehicle to an auditory environment whilst preventing the flow of gases to the auditory environment, the sound bypass device comprising: a sound inlet configured to receive gases exiting or entering the engine of the vehicle; a sound outlet configured to transmit sound pulses to the auditory environment; a chamber connected to the sound inlet at a first end and to the sound outlet at a second end, the chamber being enclosed between the sound inlet and the sound outlet; and a first membrane located within the chamber, the first membrane being configured to transmit engine-generated sound pulses from the gases whilst preventing the movement of gases through the sound bypass device; wherein the sound outlet is defined by a second membrane extending radially from the second end of the chamber, the second membrane being configured to emit sound pulses from the chamber to the auditory environment.

Abstract: An apparatus for simulating the acoustic performance of an automotive vehicle, the apparatus comprising: a processor configured to select an electrical input to be provided to the amplifier in dependence on one or more driving conditions for the vehicle, the electrical input indicating a desired acoustic output for a vehicle and being selected from a plurality of prestored electrical inputs; an amplifier configured to receive the electrical input from the processor and to generate amplified electrical signals of the acoustic output from the electrical input; a transducer configured to generate acoustic vibrations from electrical signals received from the amplifier; and a structural panel configured for placement on the body of the vehicle, wherein the transducer is mounted to the panel such that acoustic vibrations generated by the transducer are emitted from the panel to an environment within or surrounding the vehicle.

Abstract: A sound bypass device configured to transmit engine-generated sound pulses from an engine to a sound outlet whilst preventing flow of gases to the sound outlet, the sound bypass device comprising: an input tube configured to conduct the engine-generated sound pulses from the engine; and a sound transmission device connected to the input tube at a first end and to the sound outlet at a second end, the sound transmission device comprising: a first volume connected to the first end, a second volume connected to the second end, and a flexible diaphragm separating the first volume from the second volume and configured to transfer variations in pressure in the first volume to the second volume; wherein the first volume has a cross-sectional area that is greater at the diaphragm than at the first end and the second volume has a cross-sectional area that is greater at the diaphragm than at the second end.