Key parameters for impact and airborne noise control in wood buildings

Lack of understanding of wood building noise control fundamentals motivated this study. The well-known mass law and the theory of sound transmission through isotropic and uniform plate are too simple too be effectively applied for wood construction, especially for lightweight wood-frame construction due to the complexity. Wood is not uniform, and its properties are the function of time and space. This paper presents some preliminary results from a multi-year study on the effects of other key parameters than mass on wood building noise control. The parameters currently studied in laboratory included dynamic stiffness of resilient layers and its effect on Cross-Laminated Timber (CLT) floor impact noise control, and stud torsional rigidity and static airflow resistivity of insulation materials in cavity on stud wall airborne noise control. It was found that these three material properties are very significant for noise-controlled wood wall and floor design. The lower the dynamic stiffness, the better the floor impact sound insulation; the higher the airflow resistivity and the lower the torsional rigidity, the better the wall airborne sound insulation. Further study is to establish databases of these parameters and to derive guidance for noise-controlled wood wall and floor design, modelling and for product development.