The effect of contact force parameters on the synthesized impact sound properties

One of the essential problems in sound source identification is the extraction of physical-parameter-related sound characteristics. Previous studies mainly extracted the characteristics based on impact sounds since they are broadband and can preserve most of the structural information. Nevertheless, recent studies showed that the structural admittance (system function of the structure) is independent of the external contact force. That means the contact force information in the impact sound will affect the performance of the sound characteristics. In order to make the effects of contact force more clearly, the robustness of sound characteristics against the contact force parameters is carefully studied in this paper. Firstly, the impact sound continua of a cylinder structure are synthesized through a discrete state space and modal expansion based method. Then the effects of Hertz contact parameters (determine the contact force) on the temporal waveforms, spectrums and typical auditory characteristics of the impact sounds are examined respectively. The results show that both the temporal and spectral properties of the impact sound vary with different contact parameters. For subsequent studies, the extraction and selection of physical-attribute-related impact sound characteristics should eliminate the effect of impact force or avoid the characteristics which are sensitive to the contact parameters.