Löfdahl, M., Nykänen, A., and Johnsson, R., "Prominence of Different Directions of Hub Forces and Moments in Structure-Borne Tire Noise," SAE Int. J. Passeng. Cars - Mech. Syst. 8(1):346-353, 2015, doi:10.4271/2015-01-9106.
In the automotive industry, tire noise is an important factor for the perceived quality of a product. A useful method to address such NVH problems is to combine recordings with measurements and/or simulations into auralizations. An example of a method to create structure-borne tire noise auralizations is to filter recordings of hub forces and moments through binaural transfer functions experimentally measured from the hub of the car to an artificial head in the car cabin. To create authentic auralizations of structure-borne sound, all six degrees of freedom (DOFs) of hub forces and moments and transfer functions should be included. However, rotational DOFs are often omitted due to measurement difficulty, complexity, time, and cost. The objective was to find which DOF (or DOFs) is perceived as most prominent in structure-borne tire noise. An auralization model of interior structure-borne tire noise was used. An auralization including all DOFs was compared with auralizations lacking one DOF at a time in a listening test. Auralizations lacking either all translational DOFs or all rotational DOFs were also included. Results from the listening test showed that the overturning moment (Mα) was perceived as the most prominent DOF. Removing all rotational DOFs led to a larger audible difference than removing all translational DOFs. Therefore, rotational DOFs should not be disregarded in tire noise auralization. The results suggest which DOFs are important to consider in tire and vehicle sound design.