Effects of non-acoustic factors on annoyance caused by floor impact sounds: A structural equation analysis

Previous research studies have addressed the relevance of non-acoustic factors in the perception of noise. However, the majority of these studies have focused on environmental noise, such as road traffic, railway and aircraft noises, and no attempt has been made to investigate the impact of building noises. In this paper, a conceptual model which explains the annoyance caused by floor impact sounds in apartment buildings was proposed based on previous findings and is subject to empirical testing. Online and paper questionnaire surveys were conducted in Korea and the questionnaire included questions designed to assess the impact of non-acoustic factors on annoyance caused by floor impact sounds, such as noise sensitivity and neighbourhood satisfaction. The structural equation model developed from the survey indicated that a negative relationship with neighbours resulted in greater annoyance, while a greater sensitivity to noise leaded to a greater perception of disturbance from noise. The various types of noises also produced different effects on relationship between noise annoyance and relationship with neighbours

A qualitative study of annoyance caused by floor impact sounds in apartment buildings

A qualitative study was conducted to investigate how residents in apartment buildings perceive and are affected by floor impact sounds. Semi-structured interviews were conducted in South Korea and Grounded Theory was used to analyse the data. Through three coding phases of Grounded Theory (open, axial and selective), verbatim transcripts of each interview were probed and the relationship between non-acoustic factors and noise annoyance was formulated. It was found that past experience of the issue, actual disturbance and each individual’s noise sensitivity influenced noise annoyance as causal conditions. In addition, the development from noise annoyance to coping behaviours was discovered to be influenced by intervening conditions: empathy and house or neighbourhood satisfaction. As consequences of individuals’ coping behaviours, having negative attitudes to the issue or relevant authorities, considering moving house as avoidance behaviour, health and relationship problems were identified

An experimental study of psychophysiological responses to floor impact sounds

The present study investigates the adverse effects of floor impact noise using both subjective and physiological methods. A total of 21 subjects participated in the experiments and they were instructed to press a button when they noticed a sound and rate noise annoyance. Heart rate (HR), electrodermal activity (EDA), and respiration rate (RR) were measured while subjects were exposed to floor impact sounds induced by real impact sources and standard heavyweight impact source (impact ball). It was found that noise annoyance and noticeability were highly correlated with noise levels. The floor impact sounds caused by impact ball was found to be more noticeable than real impact sounds when A-weighted maximum noise levels (LAFmax) were greater than 35 dBA. The results showed that listening to floor impact noise lowered HR and raised EDA and RR. The results also indicated that EDA and RR were significantly affected by noise levels

Influence of noise sensitivity on physiological responses to floor impact sounds

This study investigated the changes in physiological responses to floor impact sounds under a laboratory condition. A total of 34 normal-hearing participants took part in the experiment and were categorised into two groups with low and high noise-sensitivity scores. The participants were exposed to five-minute floor impact sounds produced by a standard impact noise source (an impact ball) and a real impact noise source (human footsteps). For comparison, road traffic noise was used as a reference stimulus. After being exposed to each stimulus, the participants were asked to rate annoyance. During the experiments, heart rate (HR), electrodermal activity (EDA), and respiratory rate (RR) were measured. Annoyance was found to be influenced by noise level, noise source, and noise sensitivity. All physiological responses were found to be changed significantly due to noise exposure. HR decelerated, EDA decreased, and RR decelerated for five minutes of noise exposure. The physiological responses were significantly influenced by noise sensitivity. However, there were no significant effects of noise level or noise source on the physiological responses

Impact of acoustic enviornment on work in open-plan offices across job characteristics

© Proceedings of the 26th International Congress on Sound and Vibration, ICSV 2019. All rights reserved. This study aims to investigate the impacts of acoustic environment on the relationship between job characteristics and job satisfaction. Acoustic measurements and questionnaire surveys were conducted in open-plan offices in the UK and Korea. Background noise levels were recorded for 8 hours in each office and speech transmission index (STI) and sound pressure levels were measured for quantifying the single number quantities in ISO 3382-3. A total of 324 employees from 12 offices completed a questionnaire survey. The questionnaire included questions assessing noise disturbances and speech privacy, as well as job satisfaction and job characteristics. The result confirmed the strong impacts of job characteristics on self-rated job satisfaction. Background noise levels during working hours and reverberation time were negatively associated with job satisfaction; however, there were little influences of speech privacy and noise disturbance on job satisfaction. It was also observed that speech privacy, noise disturbance, background noise level, and cultural difference (Korea and UK) had moderating effects on the relationship between job characteristics and job satisfaction. In particular, greater speech privacy and lower background noise level increased the impacts of job characteristics on job satisfactio

Effects of Exposure to Rural Soundscape on Psychological Restoration

This study aims to explore and inform the connections between rural soundscape and psychophysiological well-being. Sound recordings were conducted in the urban street as well as rural areas in the Lake District National Park in the UK. Visual images were also captured using a portable 360-degree camera. Laboratory experiments were carried out in a virtual reality (VR) environment as a case study. The experiments consisted of two sessions: 1) a visual only condition and 2) a combined audio-visual condition. For comparison with a VR environment, additional experiments were performed in a non-VR environment where still images were presented on a computer monitor screen. The subjects first watched a stressful video clip and then were exposed to one urban and two rural settings. The subjects rated their perceived tranquillity, acoustic comfort, and psychological restoration at the end of each session. During the laboratory experiments, physiological responses (heart rate: HR, electrodermal activity: EDA, and respiratory rate: RR) were measured throughout the experiment. From the results, psychophysiological responses to rural soundscapes were compared with those to urban settings. Furthermore, the effectiveness of the VR environment was discussed by comparing with the non-VR environment

Uncertainty in geometry of fibre preforms manufactured with Automated Dry Fibre Placement (ADFP) and its effects on permeability

Resin transfer moulding is one of several processes available for manufacturing fibre-reinforced composites from dry fibre reinforcement. Recently, dry reinforcements made with Automated Dry Fibre Placement have been introduced into the aerospace industry. Typically, the permeability of the reinforcement is assumed to be constant throughout the dry preform geometry whereas in reality it possesses inevitable uncertainty due to variability in geometry. This uncertainty propagates to the uncertainty of the mould filling and the fill time, one of the important variables in resin injection. It makes characterisation of the permeability and its variability an important task for design of the resin transfer moulding process. In this study, variability of the geometry of a reinforcement manufactured using Automated Dry Fibre Placement is studied. Permeability of the manufactured preforms is measured experimentally and compared to stochastic simulations based on an analytical model and a stochastic geometry model. The simulations showed that difference between the actual geometry and the designed geometry can result in 50% reduction of the permeability. The stochastic geometry model predicts results within 20% of the experimental values