Engine Sound, Basic Function - GF82.60-S-9901A

Model All (Light transporter) 

Overview 

This document contains the following information:

• Engine sound generation
• Engine noise reduction

General 

The engine sound function fulfills one of the following two functions, depending on the equipment installed:

• Simulating engine and exhaust sounds in the vehicle interior
• Reducing engine noises in the vehicle interior

Function requirement 

• Engine running.

Engine sound generation 

The following signals define the current driving condition:

• Drive program/engaged drive range
• Vehicle speed
• Engine torque
• Engine speed

The sound system amplifier control unit or the multimedia system control generates a simulated engine sound on the basis of the driving condition.

The speaker system outputs the simulated engine sound even when no audio source is active. If audio output is active, the simulated engine sound is expanded by the current audio source.

Engine noise reduction 

For the engine noise reduction function, additional microphones are integrated in the vehicle to measure the engine noises in the vehicle interior. Two microphones are located in the housings of the hands-free system microphones. Two further microphones are located in the area of the grab handles in the rear passenger compartment.

Engine noise reduction analyzes the signals of the microphones. Engine noise reduction calculates counter-signals (inverted signals) based on these signals in order to reduce audible, low-frequency engine noise in the vehicle interior at cylinder shutoff. Depending on the model, engine noise reduction is controlled by the sound system amplifier control unit.

The speaker system outputs the counter-signals even when no audio source is active. If audio output is active, the counter-signals expand the current audio source. The counter-signals overlay the engine noises in the vehicle interior and eliminate them almost entirely.

	Further basic function
	Multimedia system control, basic function		GF82.85-S-9904A
	Control units
	Sound system amplifier control unit, basic function		GF82.62-S-9890A