A note on methods for the estimation of the airborne sound insulation of timber frame structures

same time, the estimation of the airborne sound insulation of timber frame structures is a complex procedure which includes the prediction of several resonances and the analysis of a significant
decrease of the transmission loss in the low frequency range.
Three case studies are presented in the paper. The emphasis is put on the transmission
loss in 1/3 octave frequency bands of double leaf structures with gypsum panels, wood studs and a
well-damped cavity. Methods of Sharp and Davy are used for the transmission loss prediction.
Particular issues are discussed for an asymmetrically sheathed timber frame structure, wood studs
with resilient channels and staggered studs.
The paper also presents that the weighted sound reduction index is not sufficient quantity
for characterizing the airborne sound insulation of timber frame structures. Various methods are
employed for the calculation of the transmission loss of a traditional structure on a silicate base.
Characteristic differences between a silicate based structure and a timber frame structure are
highlighted. The usage of the spectrum adaptation terms is encouraged.
The paper intends to be helpful in the field of the transmission loss estimation of double leaf
structures with wood studs. Since the acoustic behavior of double leaf structures with wood studs
is certainly a complex phenomenon, there is a further need for an improvement of methods for the transmission loss estimation and single number quantities for the evaluation of the sound
insulation.