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Automotive seat rattle has a large contribution in customer NVH satisfaction, as there is a close interface between the passengers and seat. The vibration from the road and other sources in the car like the engine are transmitted to the seat through the different paths which can be the cause of rattling noise in different frequency ranges from the seat. Seat structure as well as its components can be sources of rattle noise based on their physical characteristics. Therefore the main objective of this project was to characterize the acoustic signature of the seat rattle noise which can be used for noise source identification and structural NVH optimization. For this purpose, different noise measurement and structural tests were done on a Holden VE passenger seat manufactured by FUTURIS Company.

Characterizing the acoustic properties of sound-absorbing materials is costly and time consuming. The acoustic material database helps the automotive designers design their interior trims in accordance with target level for interior noise. In this paper, a two-microphone impedance tube was used to measure the normal sound absorption coefficient. The main parameters that are used in the theoretical model for interior noise level assessment are investigated. These parameters include thickness, airflow resistivity, porosity, tortuosity, viscous and thermal characteristics length. The measured results have been validated by the theoretical models. The validation of normal sound absorption coefficient was found to be in agreement with its corresponding measurement data. Finally, the sensitivity of the sound absorption coefficient which is related to the physical properties mentioned above is further analyzed.