Our company, HAAL Acoustic Enterprise, conducts professional noise surveys. Our to-date experience in noise reduction in different branches of industry confirms the fact that noise survey underlies every effective noise-reduction project.
The main goals of the noise survey are:
- to provide detailed analysis of the noise levels of given subject,
- to determine the best possible solutions for reducing the noise.
There are two types of noise surveys: workplace and environmental.
WORKPLACE NOISE SURVEYS
They regard the noise of machines and devices located inside factory halls and other industrial buildings. If the worker resides in the vicinity of the sound source, the noise influences him directly. It can also influence him indirectly, by propagation of the sound reflected off the surfaces like walls and ceiling. To determine the optimum noise-reduction solution we use professional computer program that we created ourselves. Basing on the detailed acoustic measurements we took earlier, it presents the simulation of distribution of acoustic field on the audited workstations. It considers various parameters of the noise source, selects proper sound-absorptive and insulating materials from the database and performs analyses of the acoustic field distribution in octave bands of sound. Multiple uses of this program as the basis of our acoustic projects assured us, that calculations that it does are correct.
THE SCOPE OF THE WORKPLACE NOISE SURVEYS:
- identification of noise sources causing the excess of permissible noise levels at workstations,
- taking acoustic measurements of sound emission and propagation, to determine methods to eliminate excessive noise,
- defining possible noise-reduction solutions,
- estimating the efficiency of those solutions basing on the colored noise maps, which are computer simulations of acoustic field distribution around the source BEFORE and AFTER it is silenced,
- digital 3D modeling and visualization of chosen solutions,
- determining cost and time-table of chosen solutions.
ENVIRONMENTAL NOISE SURVEYS
They regard the noise emitted and propagated to outdoor environment by machines mostly located outside buildings (fans, air inlets and outlets, cyclones, pumps etc.) or by traffic. In those surveys, analyses are performed as the computer simulations of the sound distribution in the environment using the program HPZ'2001 Windows; version March 2012 + GRUNT, license number 0_220, created by Acoustics Laboratory at Building Research Institute.
Main tasks of the HPZ'2001 program:
- calculations of "A" sound level value in the given spot. This value is the result of functioning noise sources in the vicinity.
- determining which sources and at what rate influence the resultant level of "A" sound,
- acquiring information about the efficiency of noise barriers (if such exist) at the given observation spot.
THE SCOPE OF THE ENVIRONMENTAL NOISE SURVEYS:
- taking acoustic measurements of noise emission and propagation from main noise sources affecting the outside environment; measurements include octave analyses of noise emission level in the vicinity of the source and in relation to the distance and direction of sound propagation to the environment of protected residential area,
- determining the range and offensiveness of noise in the direction of protected area, by making suitable computer simulations,
- defining methods of noise level reduction along with theoretical estimation of efficiency of proposed solutions; this is achieved by modeling acoustic fields for each noise source; those models are based on detailed measurements taken before the sources are silenced, on proposed noise-reduction solutions and on assumed efficiency factor.
- computer visualizations of noise distribution maps BEFORE and AFTER the object is silenced,
- determining cost, particular stages of the project and possible time-tables.