Maria Di Gabriele

The influence of visual characteristics of barriers on railway noise perception.

Noise annoyance is considered as the main effect of noise, it is a complex and multifaceted psychological concept dealing with immediate behavioral and evaluative aspects. In the last decades the research has intensely investigated the correlation between noise exposure and noise annoyance, nevertheless recent studies confirm that non-auditory factors influence the noise perception of individuals. In particular audio-video interaction can play a fundamental role. Today Immersive Virtual Reality (IVR) systems allow building laboratory test providing realistic experiences of the surrounding environment to detect more accurate information about the reactions of the local population. Regarding the interventions for environmental noise control the barriers represent the main solution; however some aspects related to their visual characteristic have to be further investigated. This paper presented a case study, where a sample of residents living close to a railway line assessed noise-related aspects for several barriers with different visual characteristics in an IVR laboratory test. In particular, three main factors were analyzed: the barrier type concerning the visibility of the noise source through the screen, the visual aspect of the barrier concerning some aesthetic issues and the noise level at the receiver concerning the acoustic performance of the barrier and the magnitude of the sound source. The main results of the ANOVA analysis showed that for transparent barriers Perceived Loudness and Noise Annoyance were judged lower than for opaque barriers; this difference increased as noise level increased.

Auditory recognition of familiar and unfamiliar subjects with wind turbine noise.

Considering the wide growth of the wind turbine market over the last decade as well as their increasing power size, more and more potential conflicts have arisen in society due to the noise radiated by these plants. Our goal was to determine whether the annoyance caused by wind farms is related to aspects other than noise. To accomplish this, an auditory experiment on the recognition of wind turbine noise was conducted to people with long experience of wind turbine noise exposure and to people with no previous experience to this type of noise source. Our findings demonstrated that the trend of the auditory recognition is the same for the two examined groups, as far as the increase of the distance and the decrease of the values of sound equivalent levels and loudness are concerned. Significant differences between the two groups were observed as the distance increases. People with wind turbine noise experience showed a higher tendency to report false alarms than people without experience.

Preliminary studies on the relation between the audio-visual cues' perception and the approaching speed of electric vehicles

For decades, quiet and zero emission vehicles have been considered the challenge for researchers and for the industry. Today, despite the great results obtained in the fields of air and noise pollution, the electric vehicles (EV) and hybrid electric vehicles (HEV) have raise an important question regarding the pedestrian safety. At the speeds permitted in urban areas (<50 km/h) these vehicles are considerably quieter than the traditional ones powered by gasoline or diesel. Nevertheless the amount of auditory cues associated to the approaching of these vehicles can be reduced. This can determine an increase of the risk of accidents for the pedestrians. Even though the recent studies on this problem are focused, mainly, on the minimum sound levels and on the spectral content of the approaching vehicles, further aspects of the semantic contents change of the event should be considered. In this paper a preliminary investigation on the relationship, and possible incoherence, among the approaching speed of the...

Can urban squares be recognized by means of their Soundscape

Squares have always played important functions in urban areas, being a reference place in the citizens life. During last decades, road traffic noise has influenced the perception of the sonic environment in many squares. However, there are squares where historical and typical sound sources are still present. In both cases the sonic environment remains a feature of the square together with other factors, like the visual impact. The present paper deals with the above issue and describes an experiment aimed to study how the soundscape of a square can contribute to recognize the square itself. For this purpose some well known squares in Naples and Rome have been selected to cover a range of different characteristics. In each square binaural recordings and pictures have been taken simultaneously. Then the binaural recordings have been played back by headphone to a group of subjects in laboratory simultaneously to the display of the pictures of all squares on a screen. After listening each sound the subject was asked to choose among the pictures the one showing the square judged to have the sonic environment most appropriate to the sound just heard. The comparison between subjective responses and correct answers are in progress.

On the perception of Limited Traffic Zones asurban noise mitigation action

Abstract Environmental noise is a very important issue in modern urban agglomerations and new policies are being explored in order to reduce high sound-pressure levels from transportation and industry, especially in urban contexts. Considering this issue from the subjective perspective, environmental noise is often related to noise annoyance. Over the years, possible solutions were explored for urban sound planning beyond the mere noise control engineering techniques and a number of international projects proposed innovative approaches to deal with this issue: most of them were traffic-related. In order to support the city management, it is suitable to analyse possible indirect effects of traffic limitations on the perception of the sonic environment. Indeed, it was observed that even traffic management plans with no specific focus on noise mitigation are likely to have acoustic implications. The present study investigated the variations of the sonic environment induced by the implementation of a Limited Traffic Zone (LTZ) in the historic centre of Naples, in terms of objective parameters and perceived quality of the ‘sound’ component by means of noise and social surveys before, immediately after and one year after the LTZ implementation, in order to check for possible time effects. Results show that the sample interviewed immediately after the LTZ implementation reported overall positive opinions on the sonic environment and its variation, while the sample interviewed one year after tended to shift to more neutral opinions. This finding suggests that the LTZ could be considered an effective environmental strategy for the urban noise control, but it should be adequately actuated in order to preserve the achievements in terms of noise reduction and subjective perception by the local population.

Soundscape variation in a historical city centre due to new traffic regulation

In recent years the number of candidate historic city centers to be included in the World Heritage List is increasing. This inclusion must be supported by a Management Plan programming all intervention to be implemented for the preservation of the “outstanding universal value”. So far the Management Plans do not consider the preservation and valorization of the soundscape. Consequently, urban renewal processes are based on conservation and restoration of tangible cultural heritage, in order to increase touristic attraction and to improve the quality of life. All these efforts privilege visual perception and do not take in account the auditory perception. Soundscape of a site can be considered an intangible cultural heritage to be preserved and valorized as it constitutes a peculiar characteristic of the place. It makes the place recognizable and attractive. Recently the historic centre of Naples (Italy), as World Heritage Site, has been under renewal and for sustainable mobility the largest restricted traffic area (ZTL) in Europe has been introduced. The results of soundwalks carried out in the historic center of Naples before and after the implementation of ZTL are presented. The variations of acoustical and other environmental parameters influencing the subjective perception of environmental quality are analyzed.

Classification of urban historic areas through multi‐sensorial perception and expectation.

The historic areas of cities are often under renewal processes. Although the general aims are to increase tourist attraction, to protect and restore the cultural heritage, and to improve quality of life for the local citizens, the renewal processes are generally based on architectural and design projects that privilege the visual perception. This approach does not take into account that the perception and enjoyment of the atmosphere in a historic area is a mix of phenomena that should be considered, and citizens and tourists perceive these phenomena in a dynamic way (e.g., walking along streets, crossing squares) and from different points of view. A new approach for the classification of urban historic areas is proposed. The classification is based on two emotional dimensions (calmness and vibrancy) determined by the variations of environmental parameters such as sound quality and light, and aesthetical parameters such as spatiality and urban degradation. Relationships between perceived soundscape and oth...