In 2015, a project was initiated to investigate what factors were dominating the perception of wind turbine noise in the vicinities of seven wind farms in Sweden with relatively large wind turbines. The project included, besides two listening tests, a survey of perceptual and socioeconomic factors. In a questionnaire to habitants in the vicinity of the investigated wind farms, questions were asked regarding their housing situation, living conditions, the bedroom's orientation towards wind turbines, noise disturbance, visual impact from wind turbines, economic incentive models, ownership structures, general attitudes about wind power, and more. The purpose was to provide a holistic basis for a future synthesis model for disturbance, and this project focused on the correlation between noise disturbance and visual impact from wind turbines, ownership structures and financial compensation models from the wind farm. The questionnaire was analysed with psychometric methods, including logistic regression and multivariate techniques as principal component regression. The results of the psychometric analyses showed a large spread in sensitivity to disturbances (both visual and acoustic) from wind power plants, but the most difficult elements could be identified for various factors in the questions, including e.g. audial and health factors, and the quality of financial compensation.

The low-frequency properties of a room (where statistical methods in the standards cannot be applied directly) are often hard to estimate due to strong modal behaviour. The situation gets complicated by the fact that variations in the furnishing can have an impact on the modal patterns and therefore can also influence the results of measurements at certain points, in spite of the room properties being the same. The latter can hinder the achievement of acoustic comfort in dwellings, even if they comply with the current regulations, especially due to the fact that low-frequency noise is left outside the scope, since the standards currently in force do not require measurements below 100 Hz (albeit Sweden set 50 Hz as lower limit). This article aims to study variations of the sound field that results of varying the position of three moderately absorbing boards, which emulate how very sparse furniture can impact the sound field when relocated in the room. Furthermore, the potential of numerical models as prediction tools for such problems is pointed out.

New recommendations for environmental noise levels have been issued in Sweden. The permissible levels at facades of new buildings have been increased, which has resulted in a risk for higher indoor low frequency noise levels, since the recommended indoor levels are A-weighted. The additional Swedish low frequency third octave band requirements might be violated. Therefore, there is a need for reviewing how well façade insulation properties are manifested in measurements, and how accurate the measurement results indicate the indoor noise situation from the residents' perspective. In this paper, the results of façade insulation measurements are compared with corresponding models, with a special attention to associated challenges (e.g. to establish representative microphone positions in low frequency sound fields). The measurements are performed in a demonstrator house, which replicates a modern single family house. The models are evaluated both with respect to the total sound energy integrated over the entire room volumes, and as sampled sound fields, where the sample points may correspond to microphone positions. The congruence of the measured and the modelled results are analysed and discussed, as well as the relevance of different approaches.

De nya svenska reglerna för tillåtna ljudnivåer vid fasader utomhus vid nybyggnation av bostäder innebär att även inomhusnivåerna påverkas, framförallt i lågfrekvensområdet. Framför allt påverkas upplevelsen av buller inomhus. Störningarna är starkast i lågfrekvensområdet, och detta förvärras av att fasader generellt är sämre i detta område i kombination med hörselns dynamik för lågfrekventa ljud.

The new Swedish regulations for outdoor sound levels at facades in housing construction in new areas will also affect indoor levels, especially low-frequency noise levels. However, the perception of indoor noise is even more affected. The disturbance or annoyance of noise is generally stronger in the low frequency range, and this is accentuated by the fact that facades are generally performing worse in this region, in combination with the dynamics of hearing in the low frequency region .