Development of a tire cavity sound measurement system for the application of field operational tests

Tire road noise is considered as the major noise source in traffic noise and as a health problem today. Existing methods to measure the tire road noise suffer from several disadvantages which led to the development of an alternative method, namely the tire cavity sound measurement method. Due to the high costs of existing prototypes, this method is not applicable for field operational tests and to conduct measurements comprehensively. In this paper we present a new tire cavity sound measurement system to fill this gap. We show a modification of a low cost acoustic sensor for the tire cavity sound measurement system to measure high sound pressure of approximately 150 dB with a low total harmonic distortion. We conducted experiments to compare the results of our system with a former developed highly accurate prototype and to evaluate our system as well as to verify the quality. The results show that our tire cavity measurement system can measure sound pressure levels of approximately 161 dB with a total harmonic distortion of -63.4 dB. The coefficient of determination of the former prototype and our system is 0.9629. The costs of our tire cavity sound measurement device with approximately 200 USD decreased by 97.14 percent compared to former prototypes (7,000 USD) without reducing the quality significantly. Our system can be applied for field operational tests to distinguish different road surfaces and to measure the quality of the road infrastructure as well as to estimate tire road noise.