LAUSR

This paper presents experimental evidence that laboratory measurements of the acoustical and related non-acoustical data is not a trivial task. This paper also shows that the prediction of the acoustical properties of this seemingly simple material is far from easy. First, there is a problem of characterising the non-acoustical properties of nano-porous membrane with standard laboratory methods. Second, there is a high uncertainty in the value of the membrane thickness which can lead to a substantial change in its predicted acoustical and related non-acoustical properties. Thirdly, there is an argument whether or not sound propagation in a nano-porous membrane can actually be treated as that in a classical porous media. The paper attempts to respond to these questions and to present new evidence that we may not know well yet the true acoustical properties of these fibres. Therefore, the key question is Are nano-fibres still an emerging noise control solution?