Sound quality evaluation of fuel supply module noise

In this paper, the noise emitted by fuel supply modules (FSM) is investigated. This component is used in passenger cars with internal combustion engines, and its sound could be detected in the vehicle cabin. The goal is to find an objective metric that could be used to evaluate a specific FSM sound. Using the relationships between four standard psychoacoustic parameters (loudness, sharpness, roughness, fluctuation strength) and sound pressure level (SPL), four sound quality metrics were found. To develop these sound quality metrics, the correlation of subjective and objective sound quality assessment was investigated. Two methods were used to collect the subjective evaluation of FSM sound – semantic differential and pairwise comparison. Before the listening tests, a pre-test was conducted to determine the verbal space for describing FSM sound. Two types of FSM were investigated (gasoline and diesel) at defined operating points. 50 respondents participated in subjective listening tests and assessed five recordings of FSM sound. Four resulting sound quality metrics have been obtained by correlation and statistical testing (e.g. weighted sum method). They have been tested and compared and the last non-linear metric (SQFSM) is recommended for further use. These metrics could be used for a first assessment of FSM noise without the need for time-demanding “jury testing”.