A device designed to be plugged into an electric socket in a vehicle, which socket constitutes part of the electrical system of the vehicle, which device, without any other connection, is able to detect the engine speed of the vehicle and convert this information to sound signals. In at least one embodiment, the device includes at least one device for detecting electrical pulses resulting from the engine speed that are unintentionally emitted from the generator, electric motor or ignition system of the vehicle, in order to record the current engine speed. Further, in at least one embodiment, the device transmits, by way of radio waves, sampled/simulated or synthetically generated noise signals based on the electrical pulses to the radio receiver/sound system of the vehicle in order to play these in or around the vehicle.