Noise mapping as a tool for urban planning

114-116<span style="mso-ansi-language:EN-US;mso-fareast-language: PT-BR" lang="EN-US">This paper discusses the findings of an earlier analysis of environmental noise pollution in the north section of the Green Line in the city of Curitiba, involving information about the objective aspects of the measured equivalent continuous sound pressure levels generated by vehicle traffic on this main thoroughfare. An assessment is also made of the environmental impact the avenue produces in a noise sensitive area. Only the main factors that determine road traffic noise, i.e., heavy vehicle flow, road conditions, and average speed of vehicle traffic, were considered in the noise maps developed here. The noise levels recorded on this road exceed the levels recommended by current legislation. This study demonstrates that taking only one control measure does not suffice to counteract noise efficiently. Instead, a plan involving various measures taken jointly is needed to effectively mitigate the problem. </span

Study of the Acoustic Suitability of an Open Plan Office Based on STI and DL2 Simulations

Many business offices around the world are organized as open plan offices. Therefore, studies about the acoustic comfort of the people who work in them have become increasingly important. The focus of this work is the acoustic evaluation of an open plan office combining several architectural characteristics and levels of ambient noise. This evaluation was performed through a computational model calibrated from a real office. The rate of spatial decay of sound pressure levels per distance doubling (DL2) and the speech transmission index (STI) were simulated for the acoustic evaluation of the office, allowing for the determination of the radius of distraction (rD). These parameters were simulated for 6 situations using different floor and ceiling covering materials and inserting or withdrawing screens between workstations. In addition, STI and rD were simulated under two conditions of ambient noise. The results indicated that the DL2 and rD are adequate acoustic parameters for the acoustic evaluation and improvement of an open plan office. The DL2 was strongly influenced by the presence or absence of screens between workstations and by the ceiling covering material. The rD was more sensitive to changes in ambient noise

Noise mapping as a tool for controlling industrial noise pollution

262-266The purpose of this work is to identify the contribution of noise from external sources to the noise pollution generated by a factory, by comparing sound pressure levels measured in its surroundings and those calculated by noise mapping. A metal-mechanical manufacturing plant was chosen and sound pressure levels were measured at discrete points along two rings around it, called receivers. The noise measurement data from the first ring were entered into the Sound Plan software to determine, through iteration, the factory’s main noise sources. The software then used this information to calculate noise maps and sound pressure levels at the receiver’s positions in the second ring. Finally, the contribution of noise from external sources to the overall noise generated by the factory was determined by comparing the noise measured in the second ring with the simulated data. The placement of partial barriers along some critically noisy walls was found to be effective in controlling nighttime noise, ensuring that the sound level limit for this type of neighborhood, which is established by technical standards for environmental noise as Leq = 60 dB (A), is not reached