Electrical engine sound

The outside sound is implemented by an acoustic sensor. The acoustic sensor essentially consists of a stainless steel housing with integrated speaker. The ASD control unit activates the acoustic sensor.

Acoustic sensor is active as soon as the vehicle is ready for driving. Acoustic sensor is active across the entire speed range.

The outside sound becomes audible once a significant torque is applied at the electric motor (from approx. 10 Nm).

Via the CAN-Bus, the ASD control unit receives numerous parameters (e.g. engine speed, driving speed, accelerator pedal position, load signal, engaged drive position) for the calculation of the output signals.

The central functionality of the ASD control unit is the synthesis of these output signals. The integrated digital sound processor generates an analogue signal. The generated signal is combined with the audio signal. Here, the ASD control unit functions as a sound generator. The ASD control unit varies this additional signal according to the relevant driving condition and pedal sensor position. The ASD control unit directly activates the acoustic sensor via an output stage.

Courtesy of BMW OF NORTH AMERICA, INC.

Acoustic sensor enables an outside sound when driving forwards and reversing.