Revised Criteria for Noise in Buildings
About: This article is published in Noise Control.The article was published on 1957-01-01. It has received 76 citations till now. The article focuses on the topics: Noise.
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TL;DR: The results suggest that placing barriers around tables can be an effective way to achieve good verbal-communication quality in EEs, and that subdividing large EEs into smaller ones can also be effective.
Abstract: This paper discusses the prediction of verbal-communication quality in eating establishments (EEs). EEs contain talkers and listeners who require high speech intelligibility at their tables, and high speech privacy between tables. Using catt-Acoustic, verbal-communication quality--quantified by speech transmission index (STI)--in models of three existing EEs was predicted. Talker voice-output levels were predicted using an existing empirical model accounting for the Lombard effect. With these, catt-Acoustic predicted impulse responses, speech levels and noise levels at primary and secondary listener positions, and the corresponding STIs. The untreated EEs were first modeled for various talker and listener positions, and occupancies. Then various treated configurations, involving reduced volume, increased absorption and barriers were studied to determine the effectiveness of the treatments. The results suggest that placing barriers around tables can be an effective way to achieve good verbal-communication quality. Increasing the absorption of the room surfaces or decreasing the ceiling height to control reverberation may not be effective. However, increasing the surface absorption and putting barriers around tables may achieve optimal speech conditions in EEs. Subdividing large EEs into smaller ones can also be effective.
4 citations
TL;DR: In this paper, the A-weighted equivalent continuous sound pressure level (LAeq) and factors extracted from the autocorrelation function (ACF) and interaural cross-correlation (IACF), were evaluated using a paired comparison method.
Abstract: Air conditioners are regarded as a major source of noise in built environments. Although noise control technology has reduced the sound produced by air conditioners to a comparatively low level, some people may still feel that certain aspects of the sound quality lead to discomfort. Indeed, both the sound level and the sound quality of an air conditioner can affect user’s acoustic comfort. The aim of this study was to determine the factors that significantly influence the subjective response to the sound of air conditioners. We assessed the A-weighted equivalent continuous sound pressure level (LAeq) and factors extracted from the autocorrelation function (ACF) and interaural cross-correlation (IACF). Subjective loudness, sharpness, and annoyance were evaluated using a paired comparison method. Multiple regression analyses were performed using a linear combination of LAeq, the ACF factors, IACF factors, and assessment of their standard deviations. The multiple regression analyses indicated that LAeq, the delay time of the first maximum peak, the width of the first decay of the ACF, and the magnitude and width of the IACF could predict subjective responses to air conditioner sounds.
4 citations
28 Dec 2019
TL;DR: Industrial environment as powerhouses of hydroelectric plants similar to those studied does not favor the installation of offices without interfering with the acoustic comfort and oral communication of the users, being necessary an adequate project for prolonged use in intellectual works.
Abstract: The clarity in communication, comfort, and concentration are critical issues in the performance and productivity of professionals who use offices in industrial environments. The evaluation of acoustic comfort in these offices should consider the measurement of sound pressure levels (SPL), reverberation times (RT), as well as the quantification of background noise and speech intelligibility. The present research aims to evaluate acoustic comfort in office environments located in the powerhouse of a hydroelectric plant. For this, the investigation was based on the evaluation of the interference of background noise and TR in speech intelligibility of six office rooms from three office buildings, based on NPS measurements, quantification and analysis of the NC and RC Mark II noise criterion curves, and the Speech Transmission Index (STI). The six indoor environments were also evaluated through the calculation of the TR of Sabine and Eyring. All office rooms did not meet the comfort criteria of the NC 40 curve, had unbalanced spectra between 125 and 500 Hz and perceptible vibrations at low frequencies (16 or 31.5 Hz) that exceeded 75 dB. Four rooms attended recommended TR values, remaining between 0.3 and 0.5 seconds. The STI was rated between bad and reasonable, ranging from 0.2 to 0.5. It can be concluded that industrial environment as powerhouses of hydroelectric plants similar to those studied does not favor the installation of offices without interfering with the acoustic comfort and oral communication of the users, being necessary an adequate project for prolonged use in intellectual works.
4 citations
Cites background from "Revised Criteria for Noise in Build..."
...Com os resultados de níveis de pressão sonora medidos foi possível avaliar o conforto acústico mediante as curvas NC (BERANEK, 1957; ABNT, 2017) e RC Mark II (BLAZIER JR, 1997)....
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...Com os NPS medidos (Tabela 3) foi possível avaliar o conforto acústico mediante as curvas NC (BERANEK, 1957; ABNT, 2017) e RC Mark II (BLAZIER JR, 1997)....
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...…em Arquit. e Constr., Campinas, SP, v. 10, p. e019029, 2019, ISSN 1980-6809 Avaliação por meio das curvas critério NC As curvas de critério de ruído (NC) foram desenvolvidas por Beranek (1957) para estabelecer situações satisfatórias para a inteligibilidade da fala e convivência geral em ambientes....
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TL;DR: In this article, the authors consider the powerplant noise in terms of disk loading, progressing from jets at the high end down through fans, propellers, and rotors, leading to selection of rotors and propellers for shorthaul propulsion.
Abstract: An increase of background noise has accompanied the steady growth of industrial society. Rapid growth of air travel has focused special attention on aircraft noise, and need for abatement. Anticipated growth of short-haul air transport will bring vertiports into established commercial areas and low-altitude flyovers to populated areas. Noise intrusion may be assessed in perceived noise (PNdb) for residential communities, but a more realistic yardstick for commercial/industrial sections might be speech interference level (SIL). Achievement of the ideal goal—no intrusion of noise above ambient levels—requires reduction of powerplant noise but may be limited by aerodynamic noise from the vehicle itself. Consideration of powerplant noise in terms of "disk loading," progressing from jets at the high end down through fans, propellers, and rotors, leads to selection of rotors and propellers for shorthaul propulsion. Further noise reduction below current state-of-the-art levels will require intensive long-range development programs. Parallel to concentrated effort by industry to provide aircraft acoustically acceptable to the community, the community should plan for these aircraft by judicious selection of vertiport sites and utilization of zoning and building-code functions for development of surrounding neighborhoods.
4 citations