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Acoustic comfort is a concept hardly described in the literature. But it has been used in engineering typically to refer to low noise or annoyance in order to invoke no discomfort. Current standardized methods for airborne and impact sound reduction are deployed to assess acoustic comfort in dwellings. However, the measured sound pressure levels do not represent comfort. The latter should include further the human perception of the acoustic environment. Therefore, this article reviews studies that approached acoustic comfort through the association of objective and subjective field data, combining in situ acoustic measurements and survey responses from residents. We evaluated the studies using Bradford Hill's criteria. Most researches focus on self-reported noise annoyance while some others on satisfaction responses. Many studies were found incomprehensibly described: often vital data of statistical evaluation or study design are lacking. The results indicate that noise is a significant issue in living environments, especially certain impact noise types. The use of extended low-frequency spectra down to 50 Hz was suggested for impact measurements in order to predict better self-reported noise response. Greater problems with low-frequency transmission are displayed in lightweight structures which perform inefficiently compared to heavyweight components. Harmonization of presented results and study design details should be taken into account for future articles.

Raman microspectroscopy has been shown to be a very powerful technique for the identiÐcation and characterization of small mineral Ðbres, with little or no sample preparation. Such spectra are sensitive to the composition of the mineral and can often be used to distinguish between similar species. The technique can be employed for the identiÐcation of single micrometre-sized Ðbres. Vibrational spectra were obtained from Ðve asbestos reference standards for comparison with four non-Ðbrous analogues. The di †erent species such as amosite, anthophyllite, chrysotile, crocidolite and tremolite give distinct spectra. Apparently no important di †erences appear between spectra of asbestos Ðbres and their non-Ðbrous forms, except in the OH-stretching region. For each spectrum, all peaks were listed in order to determine spectral features. The reference spectra were used for the identiÐcation of known and unknown (industrial samples) Ðbres on cellulose acetate Ðlters.