Knowledge of the uncertainty of measurement of testing results is important when results have to be compared with limits and specifications. In the measurement of sound insulation following standards ISO 140-4 and 140-5 the uncertainty of the final magnitude is mainly associated to the average sound pressure levels L1 and L2 measured. However, the study of sound fields in enclosed spaces is very difficult: there are a wide variety of rooms with different sound fields depending on factors as volume, geometry and materials. A parameter what allows us to quantify the spatial variation of the sound pressure level is the standard deviation of the pressure levels measured at the different positions of the room. Based on the analysis of this parameter some results have been pointed out: we show examples on the influence of the microphone positions and the wall characteristics on the uncertainty of the final magnitudes mainly at the low frequencies regime. In this line, we propose a theoretical calculus of the standard deviation as a combined uncertainty of the standard deviation already proposed in the literature focused in the room geometry and the standard deviation associated to the wall vibrational field.

49th Winter School on Wave and Quantum Acoustics constituted platforms for sharing the results and achievements obtained in different branches of physical acoustics, as molecular acoustics, quantum acoustics, acousto-optics, magnetoacoustics, photoacoustics, acoustics of solid state, acoustic emission, and others. Moreover, researches in some selected topics related to those mentioned above (e.g. optoelectronics, relaxation processes) were presented during the school.

The conference consisted of the 16th Workshop on Acoustoelectronics and the 16th Workshop on Molecular Acoustics, Relaxation and Calorimetric Methods. However, the organizers are opened to organizing workshops on other subjects in future. We would like to invite scientific centers and other professional groups to cooperate in organizing workshops on the subjects of their interests.

XLVIIIth Winter School on Environmental Acoustics and Vibroacoustics was a forum for all environmental and vibroacoustics fields. Particularly it was concerned with traffic noise, vibroacoustics of machines, room acoustics, building acoustics, noise protection and similar problems. During the Conference, seminars on “Measurement of noise and vibration at the workplace” and Environmental noise monitoring”, combined with measurement workshops, were organised in association with SVANTEK.

The Conferences began with the special, joined session dedicated to celebration of the 15th Jubilee Conference Integrated Optics – Sensors, Sensing Structures and Methods. In summary, 48 people participated in Conferences and seminars, presenting 37 lectures, reports and posters. In this issue one can find abstracts of some lectures and posters, which were presented during the Conferences.