Preliminary results in developing an acoustic sound simulator*

Noise, vibration and harshness (NVH) simulators are used in the automotive industry to help engineers diagnose and resolve sound quality issues during the development process. Transfer functions are measured between individual sound sources and the driver’s head using a prototype model or a model of a similar make. The transfer function is converted to an impulse response and convolved with a source signal to simulate what a driver hears. Filters are applied to the transfer function to simulate changes in the automobile.

The development of heavy machinery would also benefit from an NVH simulator, but can have drastically different components and intended functions. A physics-based model would allow for unbuilt machinery to be tested in the design stage for sound quality. To begin to understand and implement this model, transfer functions were measured for some simple structures consisting of one to several members and used to generate a simulated signal. These signals were compared to the measured response of the system. Post-processing techniques were also investigated to improve the overall quality of the simulated response.