An experimental study on noise indices in air conditioned offices

Applied Acoustics, 2015

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The International Journal of Acoustics and Vibration, 2018

The levels of noise produced in university facilities by students, increases the noise annoyance. The quality of life and the academic performance of university students could be inuenced by this factor. Unfortunately, as far as methodology is concerned, there are no regulations or standards that allow for the correct evaluation of noise annoyance at educative facilities. In this work a method for the evaluation of noise annoyance and an indicator of noise annoyance are presented. In order to obtain a numerical value, a percentage index, and a verbal index that represents the noise annoyance in a specific area at university facilities, psychoacoustic annoyance (PA) and evaluation of perception of noise annoyance has been related. Resulting from this correlation an indicator of noise annoyance was proposed. The results were associated with this indicator. The method and the proposed indicator allow for deeper evaluation of noise annoyance and facilitate the development of appropriate actions against noise.

… of the Indoor Air 2008 …, 2008

SUMMARY A human subject experiment was performed to examine the effect of office noise and temperature on human perception, comfort and office work performance. The experiment concerned offices of two different sizes with three different acoustical ...

2022

The classical approach to occupational health and safety management and control, based on measuring and reducing risk levels does not seem to be effective in improving quality of workplaces and quality of workers' life. It should be integrated with models and actions that consider objective comfort variables and the subjective perception of wellbeing during worktime. Almost everywhere, legislative and regulatory scenarios show a poor or null consideration of the non-auditory effects produced by exposure to noise and poor acoustic quality of workplaces. In this paper the acoustic quality variables are considered as components of the global comfort design of workplaces with special attention to reducing the risk of non-auditory effects on workers' health. Some results of a recently completed Italian inter-universities project on non-auditory effects of noise exposure in workplaces, with special attention to schools, are shown. Among them, a collection of guidelines referred to experiences and methods aimed at understanding the correlation between acoustic quality of and various physiological and psychological pathologies, included vocal effort, perceptive-cognitive performance and more.

Energies, 2021

Current research on human comfort has identified a gap in the investigation of multi-domain perception interactions. There is a lack of understanding the interrelationships of different physio-socio-psychological factors and the manifestation of their contextual interactions into cross-modal comfort perception. In that direction, this study used data from a post occupancy evaluation survey (n = 26), two longitudinal comfort studies (n = 1079 and n = 52) and concurrent measurements of indoor environmental quality factors (one building) to assess the effect of thermal, acoustic and air quality perception interactions on comfort and satisfaction of occupants in three mixed-mode university office buildings. The study concluded that thermal sensation (TSV) is associated with both air quality (ASV) and noise perception (NSV). The crossed effect of the interaction of air quality and noise perception on thermal sensation was not evident. The key finding was the significant correlation of op...

Noise is a common and widespread problem in workplaces. Noise can lead to hearing loss, hypertension, nervous and mental disorders, annoyance and stress, sleep disturbance, negative impact on productivity and working capacity. The undesirable effects of noise on an individual or group are called annoyance. Some personal and social characteristics can affect on annoyance. This study was aimed to assess the level of noise pollution in some hospitals in Qom, central Province of Iran and study its effects on nurses' psychological and physiological responses. The sound levels were measured using a sound level meter and the noise annoyance was assessed through a valid and reliable questionnaire. The noise annoyance index was finally defined based on variables measured by the questionnaire and its correlation with equivalent sound level at different frequencies. Besides, the major noise sources in different wards of the hospitals, the relationship between noise annoyance and demographi...

Journal of Environmental Psychology, 2015

Noise has repeatedly been shown to be one of the most recurrent reasons for complaints in openplan office environments. The aim of the present study was to investigate if enhanced and worsened noise absorption in open-plan offices is reflected in the employees' ratings of disturbances, health, and performance. For one of the floors, the manipulations were from better to worse to better acoustical conditions, while for the other the manipulations were worse to better to worse. The acoustical effects of these manipulations were assessed according to the new ISOstandard 3382-3: 2012 for open-plan room acoustics. In addition, the employees responded to questionnaires after each change. Our analyses showed that within each floor enhanced acoustical conditions were associated with lower perceived disturbances and cognitive stress. There were no effects on personal efficiency. The results furthermore suggest that even a small deterioration in acoustical room properties measured according to the new ISO-standard for open-plan office acoustics has a negative impact on self-rated health and disturbances.

The aim of this study was to investigate how irrelevant speech, temperature and ventilation rate together affect cognitive performance and environmental satisfaction in open-plan offices. In Condition A, neutral temperature (23.5 C), low intelligibility of speech (high absorption and low masking sound level) and high fresh air supply rate (30 l/s per person) were applied. This was contrasted to Condition B with high room temperature (29.5 C), highly intelligible speech (low absorption and high masking sound level) and a negligible fresh air supply rate (2 l/s per person). Sixty-five participants were tested. In Condition B, performance decrement was observed especially in working memory tasks. Based on subjective assessments, mental workload, cognitive fatigue and symptoms were higher and environmental satisfaction was lower in Condition B. It was concluded that special attention should be paid to the design of whole indoor environment in open-plan offices to increase subjective comfort and improve performance.

Buildings

Indoor acoustic quality is one of the critical indicators for occupants’ health, comfort, and productivity in contemporary office environments. Post-occupancy evaluation (POE) is usually employed to examine in situ acoustic measurements to ensure indoor acoustic quality. However, prevailing acoustic performance evaluation does not often consider the technical attributes of building systems (TABS) to holistically investigate the significant correlations between objective acoustic field measurements and subjective POE. As such, this study proposes to cross-examine in situ and perceived acoustic quality indices with TABS to quantify critical factors leading to enhanced occupant satisfaction. Statistical analyses suggest that technical building attributes can significantly influence occupants’ acoustic satisfaction compared to sound levels recorded in contemporary offices. For instance, lowering the distributed noise level from above 40% to 2% can lead to an average 21% increase in occu...

1982

Uncomfortable loudness levels were measured for two groups of subjects with either high or low scores on a noise annoyance questionnaire. The study was conducted in two stages. In the first stage scores of noise annoyance, general annoyance and locus of control were obtained from 122 respondents. Two groups of responders on the noise annoyance questionnaire attended the laboratory for the second stage involving a determination of the uncomfortable loudness level (ULL) by two methods (BCkCsy and analogue adjustment) and for two types of sound source (white noise and a 1 kHz tone). The key findings from the first stage were that (i) noise annoyance scores were not bimodal, showing no significant deviation from normality, (ii) females showed higher noise annoyance and (iii) both general annoyance and locus of control scales showed significant positive correlations with noise annoyance. Findings from the second stage showed that (i) BCkCsy determinations gave higher ULL's than those from the analogue adjustment method, (ii) based on annoyance scores, noise-annoyed subjects produced significantly higher ULL's than their less annoyed counterparts but only with the analogue determination with a 1 kHz tone, (iii) females produced markedly lower ULL's than males and (iv) deactivation, locus of control and extroversion were identified as mediating factors in the setting of the ULL. The results were further discussed in terms of methodological differences between this and earlier studies.