Impact of Liquid Applied Sound Damping Treatments on Sound Quality as Measured via Psychoacoustic Metrics 2023-01-1054

Electric vehicle (EV) drivetrains typically produce lower magnitude broadband noise than internal combustion engines. However, EVs can produce annoying, high-frequency tonal sounds particularly noticeable to the human ear. Psychoacoustic metrics aim to characterize sounds based on human perception and have increasingly been employed to understand noises within an EV that are undesirable and in need of additional acoustic mitigation treatments. Liquid applied sound damping (LASD) coatings are one method employed to minimize unwanted noises within a vehicle. LASD is typically applied to metal components of the vehicle body to dampen vibrations in the structure through the coating's viscoelastic properties. The damping performance of LASD can be tuned to address different frequency ranges through formulation, application conditions, and polymer design. Herein, we investigate how those same variables affect the resulting sound emanating from vibrating panels coated with LASD, with particular attention to the psychoacoustic profile produced. Tying LASD design parameters to psychoacoustic improvements provides a strong methodology for selecting materials best suited to address acoustic mitigation opportunities in EVs.