Improving Acoustic Properties of Multilayer Soundproofing Boards

The Japan Automobile Research institute (JARI) has determined that it is possible to improve the performance of multilayer soundproofing boards in automobiles while at the same time reducing their weight.

The JARI tested the acoustic properties of multilayer soundproofing boards used in automobile floors, dashboards, and roofs, to obtain data on sound transmission loss, impact sound reduction levels and sound absorption coefficients for these components. These data were then subjected to multiple regression analysis, which provided information on the acoustic effects of soundproofing board materials, including asphalt sheet, felt, carpet, etc. Regression modelling was then used to determine how altering the weight and thickness of component materials would affect acoustic performance. The results of these simulations were confirmed in actual testing.