Effect of sound-related activities on human behaviours and acoustic comfort in urban open spaces

Human activities are important to landscape design and urban planning; however, the effect of sound-related activities on human behaviours and acoustic comfort has not been considered. The objective of this study is to explore how human behaviours and acoustic comfort in urban open spaces can be changed by sound-related activities. On-site measurements were performed at a case study site in Harbin, China, and an acoustic comfort survey was simultaneously conducted. In terms of effect of sound activities on human behaviours, music-related activities caused 5.1–21.5% of persons who pass by the area to stand and watch the activity, while there was a little effect on the number of persons who performed excises during the activity. Human activities generally have little effect on the behaviour of pedestrians when only 1 to 3 persons are involved in the activities, while a deep effect on the behaviour of pedestrians is noted when > 6 persons are involved in the activities. In terms of effect of activities on acoustic comfort, music-related activities can increase the sound level from 10.8 to 16.4 dBA, while human activities such RS and PC can increase the sound level from 9.6 to 12.8 dBA; however, they lead to very different acoustic comfort. The acoustic comfort of persons can differ with activities, for example the acoustic comfort of persons who stand watch can increase by music-related activities, while the acoustic comfort of persons who sit and watch can decrease by human sound-related activities. Some sound-related activities can show opposite trend of acoustic comfort between visitors and citizens. Persons with higher income prefer music sound-related activities, while those with lower income prefer human sound-related activities

Applications of Bound States in the Continuum in Photonics

The intriguing properties of bound states in the continuum (BICs) have attracted a lot of attention in photonics. Besides being effective in confining light in a counter-intuitive way, the correspondence between the near-field mode pattern and the far-field radiation of BICs manifests the fascinating topological characteristics of light. Early works on photonic BICs were mainly focused on designing artificial structures to facilitate their realization, while recent advances have shifted to exploring their exceptional properties in applications. In this review, we survey important breakthroughs and recent advances in this field. We detail the unique properties of BICs, including light confinement enhancement, sharp Fano resonances, and topological characteristics. We provide insights into the unique phenomena derived from BICs and the impact of BICs on various applications. We also discuss the paradigm shift enabled or facilitated by BICs in several emerging research frontiers, such as parity-time symmetric systems, higher-order topology, exciton-photon coupling, and moir\'e superlattices

Field study on the influence of spatial and environmental characteristics on the evaluation of subjective loudness and acoustic comfort in underground shopping streets

A large-scale measurement and subjective survey was undertaken in five underground shopping streets to determine the influence of spatial and environmental characteristics on users’ subjective loudness and acoustic comfort. The analysis on the spatial characteristics shows that the subjective loudness is higher in “street type” than in “square type” underground shopping streets when the equivalent continuous A-weighted sound pressure level (LAeq) is relatively high (75 dBA). Acoustic comfort is higher in “square type” than in “street type” underground shopping streets where LAeq is relatively low (55 dBA). Considering spatial functions, it is found that acoustic comfort is higher in a dining area than in a shopping area. In terms of environmental characteristics where air temperature, relative humidity, luminance and visual aspect were considered, the subjective loudness is influenced by humidity and luminance, with correlation coefficients of 0.10 to 0.30. The evaluation of acoustic comfort is influenced by air temperature, humidity, and luminance, with correlation coefficients of 0.1 to 0.4. There are significant correlations between the evaluation of environmental factors and subjective loudness, as well as, acoustic comfort. The correlation coefficients are 0.1 to 0.5. Moreover, respondents’ attitude to sound environment could influence their evaluation of subjective loudness and acoustic comfort

Effects of individual sound sources on the subjective loudness and acoustic comfort in underground shopping streets

Previous studies have demonstrated that human evaluation of subjective loudness and acoustic comfort depends on a series of factors in a particular situation rather than only on sound pressure levels. In the present study, a large-scale subjective survey has been undertaken on underground shopping streets in Harbin, China, to determine how individual sound sources influence subjective loudness and acoustic comfort evaluation. Based on the analysis of case study results, it has been shown that all individual sound sources can increase subjective loudness to a certain degree. However, their levels of influence on acoustic comfort are different. Background music and the public address system can increase acoustic comfort, with a mean difference of 0.18 to 0.32 and 0.21 to 0.27, respectively, where a five-point bipolar category scale is used. Music from shops and vendor shouts can decrease acoustic comfort, with a mean difference of -0.11 to -0.38 and -0.39 to -0.62, respectively. The feasibility of improving acoustic comfort by changing certain sound sources is thus demonstrated

The effect of foreground and background of soundscape sequence on emotion in urban open spaces

This paper discusses the influence of the soundscape sequence of different urban open spaces on emotion. Thirty participants with normal hearing were selected to listen to forty-two different acoustic sequences and report their emotional changes during the process. The data were analysed in four stages, and the results are as follows: First, emotional response highly correlates with background type. Only when the foreground is negative does it relate to the foreground type. Second, the positive foreground in the early part of a sequence, or the neutral (or negative) foreground in the later part of a sequence, induces a better emotional experience. Third, in an acoustic sequence, emotion changes along with a change in the foreground. The appearance of the foreground triggers emotional fluctuations, and the end of the foreground is followed by emotional recovery. Finally, combining foregrounds can aid in regulating negative emotions. This effect is related to the position of the positive foreground and background type. We offer suggestions on the design of urban soundscape from the perspective of emotion based on the findings

Analyzing the Nonlinear System by Designing an Optimum Digital Filter named Hermitian-Wiener Filter

The classical Wiener filter was engaged into identifying the linear structures, resulting in clear and incredible drawbacks in working with nonlinear integrated system. Currently, the Hermitian-Wiener system are suitable for unpredicted sub-system that consists of numerous and complex inputs. The system introduces a two-stage to analyze the subintervals where the output nonlinearities are noninvertible, through using the unknown orders and parameters. Finally, a practical strategy would be discussed to analyze the nonlinear parameters

Red Soundscape Index (RSI): An index with the potential to assess soundscape quality

It is not enough to define urban soundscape just using the green soundscape index (GSI), which is the ratio of the perception of natural sounds to the perception of traffic noises. Therefore, in the present study, red soundscape index (RSI), defined as the ratio of perception of natural sounds to perception of human sounds, was introduced. The data for calculating RSI were collected from sound environment measurements and a questionnaire-based survey in seven urban parks in Harbin city, China. The results revealed the following: (1) RSI was correlated with the overall soundscape quality; (2) RSI was correlated with the maximum and minimum instantaneous sound pressure levels and with equivalent sound pressure levels; and (3) The urban sound environment as well as sound quality can be classified by RSI. It was confirmed that RSI could be used as a supplement to GSI in urban soundscape planning