Acoustical planning for workplace health and well-being: A case study in four open-plan offices

Noise is the most frequent reason for complaints about environmental conditions in the workplace. It is associated with individual health and well-being and decreased productivity and performance. This study identified a set of acoustic strategies for open-plan workplaces and examined a case study applying those to four open-plan offices in the United States. The set of measures was defined based on a literature review and a focus group interview with 17 experts. A total of four topics were identified as key performance indicators of proper acoustic environments in the open-plan workplaces. A total of 19 items were then developed within these 4 topics as the protocols for planning acoustic strategies for workplace health and well-being. In the case study, the level of acoustic performance for workplace health and well-being was highest in the Dallas office (27.5 points out of a total of potential 40.0) followed by the Minneapolis office (26.0). Both offices outperformed the other offices in achieving space planning principles to control noises and occupant noise control in open spaces for acoustical privacy. A further examination on the relationships between acoustic strategies and other health and well-being key performance indicators in these offices suggests that guidance to increase occupants’ auditory comfort, well-being, and performance should be sought by designers in a holistic and integrative way

Associations between personal attitudes towards covid-19 and public space soundscape assessment: An example from antwerp, Belgium

The COVID-19 pandemic, and the lockdown events and policies that followed, led to significant changes in the built environment and how it is experienced by people and communities. Among those, variations in the acoustic environments were some of the most noticeable in cities. This study investigated the relationships between the perception of the acoustic environment (i.e., sound-scape) and different personal factors such as attitudes towards the pandemic and noise sensitivity, by performing a survey with 109 participants in an urban green public space in Antwerp (Belgium), shortly after most restrictions issued by the government were lifted in September 2020 when the first contamination wave ended. While preliminary in nature, the results of this data collection campaign show that people actively changing their behaviors (using less public transport or cycling more) assessed the soundscapes as less vibrant/exciting. People who were more concerned about the pandemic tended to notice more natural sounds and noise from traffic on nearby local roads. This same subset also put a bigger importance on the environmental quality of the public space than in the pre-pandemic period. Noise sensitivity also played a role, as an association was found between more-than-average noise sensitive persons and those more worried regarding the pandemic. Overall, the findings of this study confirm that at least part of the people have started to perceive the public space, including its soundscape, differently since the start of the pandemic

Sound Environments in Large Public Buildings for Crowd Transit: A Systematic Review

Sound environments in large public buildings are likely to be different from those of performance spaces, as well as those not specifically designed for acoustic “performance”, but where sounds still play an important role because of the function they can promote (or disrupt). The aim of this study was identifying common strategies and empirical approaches researchers have been implementing for these acoustically complex enclosures and to provide some methodological indications for future studies on the topic. Studies conducted in three building types for crowd transit, such as museums/exhibition spaces, shopping malls, and transportation hubs/stations, which were collecting data about either physical outcomes or individual responses for such sound environments, were selected. The Scopus databases were searched for peer-reviewed journal papers published in English without time limitations. An additional manual search was performed on the reference lists of the retrieved items. The general consideration on inclusion was to meet the requirement that the case belonged to the three building types, and then the specific inclusion criteria were: (1) including at least an objective acoustic measure of the space; or (2) including at least a subjective measure of the space. The search returned 1060 results; after removing duplicates, two authors screened titles and abstracts and selected 117 papers for further analysis. Twenty-six studies were eventually included. Due to the limited number of items and differences in measures across studies, a quantitative meta-analysis could not be performed, and a qualitative approach was adopted instead. The most commonly used objective measures were SPL, and more specifically often considered as LAeq, and T. The intervals across studies were currently of inconsistency, and the selection is recommended to take space scale factor into account. The used subjective measures can be classified into four categories as annoyance, affective quality, room-acoustic quality, and acoustic spatiality. Four basic perceptual assessments concerning dynamic contents are accordingly suggested as “annoying-not annoying”, “crowded-uncrowded”, “long-short (reverberation)”, and “far away-nearby”. The other descriptors can be project-specific. The methodologies involve measurement, questionnaire/interview, listening test, and software simulation. It is necessary for the former two to consider temporal and spatial features of such spaces, and the adoption of the latter two will lead to better understanding of users’ exposure in such spaces, e.g., acoustic sequences and user amount. The outputs of investigations inform that background noise level, e.g., 90 dB in museum/exhibition spaces, and sound reverberation, e.g., 4.0 to 5.0 s in shopping malls and transportation hubs/station, are of fundamental importance to the design of such spaces. Sufficient acoustic comfort can be achieved with integrated design of indoor soundscape

Changes in the Soundscape of the Public Space Close to a Highway by a Noise Control Intervention

The deployment of measures to mitigate sound during propagation outdoors is most often a compromise between the acoustic design, practical limitations, and visual preferences regarding the landscape. The current study of a raised berm next to a highway shows a number of common issues like the impact of the limited length of the noise shielding device, initially non-dominant sounds becoming noticeable, local drops in efficiency when the barrier is not fully continuous, and overall limited abatement efficiencies. Detailed assessments of both the objective and subjective effect of the intervention, both before and after the intervention was deployed, using the same methodology, showed that especially the more noise sensitive persons benefit from the noise abatement. Reducing the highest exposure levels did not result anymore in a different perception compared to more noise insensitive persons. People do react to spatial variation in exposure and abatement efficiency. Although level reductions might not be excessive in many real-life complex multi-source situations, they do improve the perception of the acoustic environment in the public space

Differences in soundscape appreciation of walking sounds from different footpath materials in urban parks

The perception of the acoustic environment, namely the soundscape, in urban parks has attracted increasing attention. There is a growing belief that the management of the acoustic environment of urban parks should be addressed within a broader soundscape methodology rather than a merely noise control one. One of the most frequent sound sources in urban parks is walking sound; however walking sound perception so far has mainly been investigated for indoor environments. This paper aims to investigate the overall effect of walking sounds from different walked-on materials on people's soundscape, combined with other non-acoustical factors. Moreover, this research investigates how perception varies when the walking sound is self-produced or simply listened. To this purpose, two laboratory experiments in Italy and UK were carried out with four walked-on materials that were considered to be possible design solutions for the footpaths of urban parks: grass, wood, stone and gravel. Results showed a significant effect of materials on perceived noise annoyance and soundscape quality, as well as a partial influence of other nonacoustical factor. Considering the individual responses for the four selected materials, gravel was associated to the worst soundscape quality (M = 38.42) while grass to the best one (M = 65.05). While a group effect (Italian and UK samples) was observed for perceived noise annoyance corresponding to the materials, no significant group effect was found for soundscape evaluation. Eventually, people simply listening to the walking sounds resulted to be less tolerant towards them, with respect to people who self-produced the sounds by walking

Measurements of acoustical parameters in the ancient open-air theatre of Tyndaris (Sicily, Italy)

The emerging field of archaeoacoustics is attracting increasing research attention from scholars of different disciplines: the investigation of the acoustic features of ancient open-air theatres is possibly one of its main themes. In this paper, the outcomes of a measurement campaign of acoustical parameters in accordance with ISO 3382-1 in the ancient theatre of Tyndaris (Sicily) are presented and compared with datasets from other sites. Two sound sources were used (firecrackers and dodecahedron) and their differences were analysed. A very good reproducibility has been shown between the two measurement chains, with differences on average of 0.01 s for reverberation time T20, and less than 0.3 dB for Clarity C50 and C80 and for sound strength. In general, results show that the reverberation time and strength of sound values are relatively low when compared with other theatres because of the lack of the original architectural element of the scaenae frons. When combining this effect with the obvious condition of an unroofed space, issues emerge in terms of applicability of the protocols recommended in the ISO standard. This raises the question of whether different room acoustics parameters should be used to characterise open-air ancient theatres

Introducing a Method for Intervals Correction on Multiple Likert Scales: A Case Study on an Urban Soundscape Data Collection Instrument

Likert scales are useful for collecting data on attitudes and perceptions from large samples of people. In particular, they have become a well-established tool in soundscape studies for conducting in situ surveys to determine how people experience urban public spaces. However, it is still unclear whether the metrics of the scales are consistently interpreted during a typical assessment task. The current work aims at identifying some general trends in the interpretation of Likert scale metrics and introducing a procedure for the derivation of metric corrections by analyzing a case study dataset of 984 soundscape assessments across 11 urban locations in London. According to ISO/TS 12913-2:2018, soundscapes can be assessed through the scaling of 8 dimensions: pleasant, annoying, vibrant, monotonous, eventful, uneventful, calm, and chaotic. The hypothesis underlying this study is that a link exists between correlations across the percentage of assessments falling in each Likert scale category and a dilation/compression factor affecting the interpretation of the scales metric. The outcome of this metric correction value derivation is introduced for soundscape, and a new projection of the London soundscapes according to the corrected circumplex space is compared with the initial ISO circumplex space. The overall results show a general non-equidistant interpretation of the scales, particularly on the vibrant-monotonous direction. The implications of this correction have been demonstrated through a Linear Ridge Classifier task for predicting the London soundscape responses using objective acoustic parameters, which shows significant improvement when applied to the corrected data. The results suggest that the corrected values account for the non-equidistant interpretation of the Likert metrics, thereby allowing mathematical operations to be viable when applied to the data

An Experimental Study on the Influence of Soundscapes on People’s Behaviour in an Open Public Space

Several studies have investigated how environmental sounds and music can modulate people’s behaviours, particularly in marketing research. However, there are relatively few examples of research about such relationships with a focus on the management of urban public spaces. The current study investigated an open public space used mainly as a pedestrian crossing to analyse the relationship between the audio stimuli and peoples’ behaviours. An experiment relying on covert behavioural observation was performed. During the experiment, three different music stimuli and a control condition (i.e., no music) were reproduced in order to find out firstly whether music compared to no music could elicit an increase in the number of people stopping in the investigated area, and secondly whether music is associated with a longer duration of stay for those who stop. Results showed that the presence of music had no effect on the number of people stopping in the area, but it had a statistically significant effect on the duration of stay for those who stopped. The above findings support the idea that people felt more invited to stay in the area with music rather than with no music, and suggest that the acoustical manipulation of the existing sound environment could provide soundscape strategies capable of promoting social cohesion in public spaces

Assessment methods and factors determining positive indoor soundscapes in residential buildings: A systematic review

The design of an indoor acoustic environment positively perceived by building occupants requires a perceptual approach to be adopted in order to define what makes it sound good. Soundscape standards ISO 12913 have been introduced to assess how the acoustic environment is perceived, in context, by people. According to the standards, a straightforward characterization of a soundscape as positive is currently possible only through measurements by persons, because of a current gap in linking perceptual metrics to acoustic or psychoacoustic measurements. In addition, despite applying also to indoor contexts, methods and perceptual metrics described by the standards have been mainly derived from studies related to outdoor urban environments and it is not clear whether they could be directly applied indoor. For this reason, a systematic review was performed to investigate: (i) Data collection methods used in the literature for indoor residential soundscapes and (ii) factors, output of such methods, that characterize them positively. For this purpose, a systematic review has been conducted in accordance with the PRISMA guidelines (preferred reporting items for systematic reviews and meta-analyses) guidelines. The Scopus database was searched for peer-reviewed journal papers published in English, between 1 January 2009 and 24 June 2019, including: (1) field or laboratory studies relevant to residential buildings and (2) studies assessing factors that influence the perception by building users of indoor acoustic environments. The search excluded studies related to: (a) Speech perception issues; (b) noise-induced sleep disturbance; (c) acoustic perception by hearing impaired building users; (d) perception of vibrations or impact sounds. The search returned 1087 results. After the screening process, 37 articles were finally included. Given the differences in methodologic approaches, a quantitative meta-analysis could not be performed, and a qualitative approach was adopted instead. A large part of the selected literature reflected a general effort of minimizing noise annoyance by reducing noise exposure and, in particular, noise levels. Questionnaires and guided interviews were used to capture people's perception, while the adoption of soundwalks and non-participatory behavioral studies did not emerge in the review literature and need further investigation. The evaluation of a variety of auditory sensations both in their positive and negative dimensions, beyond annoyance, would be required to explore the positive perceptual potential of sounds. Besides sound level, a variety of factors related and unrelated to the acoustic environment were found to affect perceptual outcomes and a framework of evaluation has been proposed as a reference for future assessments. Results encourage the integration of soundscape methodologies into IEQ research, in order to enhance user health and well-being

Collecting and mapping soundscape data across the 15 UK National Parks

The soundscape approach, as understood by the ISO 12913 series, is most applied in urban settings, aiming beyond noise control in order to holistically employ its quantitative and qualitative facets. On the other side, the current understanding of the soundscape concept in bioacoustics and acoustic ecology is less focused on perception. There is generally a lot of public interest in how to preserve the opportunity for people to experience the “natural quiet” and “the sounds of nature”, and the need to balance that with the protection of the natural areas and national parks from the noise that the visitors themselves generate while on site. However, specific investigations in these environments are scarce in the United Kingdom. Moreover, while there might be acoustic environments and sound sources that people identify with national parks, they are not systematically documented nor implemented in the national parks' management plans. Therefore, we propose a framework starting with a quasi-crowd-sourced acquisition of soundscape data and mapping those to a freely accessible GIS platform such as Google Earth, leading towards identifying soundscape conservation targets and management tools for the UK national parks, further raising the awareness of the value of sound as a resource