Sound Design Under the Aspects of Musical Harmonic Theory 2003-01-1508
Sound design of vehicle interior and exterior noise is becoming more and more important for the customer's impression of product quality. To accommodate for this, FEV has developed a sound design method that utilizes FEV VINS (Vehicle Interior Noise Simulation) to design series production relevant hardware modifications. Within a new internal research program, FEV's NVH specialists investigated the theory of musical harmonics and compared the results with engine acoustics in an effort to establish if and what mechanical acoustics can learn from musical harmonics.
Looking at engine acoustics from the point of view of musical harmonic theory, the specific combination of half and integer engine orders in particular offers the possibility of creating harmonious noise content. Furthermore, we can estimate how the typical subjective evaluations derive from the integer and half engine orders that occur depending on the engine concept. The melodious sound of a 6-cylinder engine can be explained, for example, by the interplay of the engine orders at different, perfectly consonant intervals, such as prime, fourth, fifth, major third and octave as well as by the absence of the tritone (augmented fourth), also known as the “devil in music”.
The insights of musical harmonic theory facilitate a more in-depth understanding of what we perceive as pleasant vehicle sound and are therefore taken into account in relevant development projects as additional design consideration parameters.