Patch NAH for Noise Source Mapping in Cabin Environments

Noise levels and noise characteristics in a car cabin are important competitive discriminators in the automotive industry today. Efficient tools for mapping and analyzing the underlying source distributions are therefore very important for automotive manufacturers. The present paper describes a system based on a hand-held microphone array with integrated position measurement and using the Statistically Optimal NAH (SONAH) calculation method to perform patch holography. The SONAH method has the big advantage as compared to traditional NAH that spatial window effects are small even when the measurement area does not fully cover the source area. The paper also presents practical measurements.