Acoustic device for a vehicle

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 extending outwardly from a central point of the sound outlet, and the second membrane being configured to move in response to sound pulses from the chamber to emit sound pulses from the chamber to the auditory environment.