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1
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Detection and Classification of Selected Noise Sources in Long-Term Acoustic Climate Monitoring

100%
Kłaczyński M., Wszołek T.
Acta Physica Polonica A
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2012
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vol. 121
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issue 1A
A-179-A-182
EN
Continuous acoustical climate monitoring of the environment raises several problems related to large quantities of the recorded data, which often represents information unrelated to the studied noise source. Manual verification of such data is time-consuming and costly. Therefore, developing effective methods for automatic identification of transport noise sources becomes an important task for the proper determination of noise levels. This paper presents a concept of such method of automatic detection and classification of the noise sources from the air and railway transportation in the acoustic environmental monitoring.
2
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The Effect of Changes in Position of Sound Source and Microphone on Acoustic Measurements in Small Rooms. A Case Study

100%
Mleczko D., Wszołek T.
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vol. 125
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issue 4A
A-131-A-134
EN
Results of computer simulations and measurements in real interior for varying location of sound source and microphone are shown in the paper. A small room with a volume of 47 m^3 was used for this purpose. The objective of measurements and calculations was to determine the sound pressure level and other parameters derived from the room impulse response (T_{30}, EDT, C_{80}, STI) followed by the sensitivity analysis of those parameters to changing the location and orientation of the sound source and the receiver. In order to determine these parameters, the room impulse response was measured using MLS method. Experimental studies have been used to verify the acoustic room model built with use of enhanced radial method algorithms and its sensitivity. That allowed complementary and extended simulation studies on the room acoustic characteristics and finally determination of sensitivity of output parameters to changes of location and orientation of the measurement channel elements.
3
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Automatic Detection of Long-Term Audible Noise Indices from Corona Phenomena on UHV AC Power Lines

100%
Wszołek T., Kłaczyński M.
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vol. 125
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issue 4A
A-93-A-98
EN
One of the most important tasks in outdoor acoustic monitoring stations is automatic extraction of the measured signal parameters. In case of corona discharge noise from ultra-high voltage alternating current (UHV AC) power lines it is necessary to select properly the corona audible noise (CAN) parameters to be monitored for noise indicators calculation, as the monitored signal and the background noise strongly fluctuate. A combined selection of distinctive features of CAN is necessary in order to distinguish the actual signal from the external interference. The vast amount of recorded data is difficult to store and process. Therefore, particular attention was devoted to define of the collected parameters used for automatic calculation of the CAN long-term noise indicators. In addition, several new CAN parameters were introduced, including spectral moments, spectral coefficients of tonal components contribution, and power coefficients in selected frequency bands; as it allowed more efficient selection of samples with non-zero contribution from CAN. The artificial neural network was applied for final classification of the measured samples. Selected and properly filtered samples provided the basis for calculations of long-term noise indicators. Efficiency of the said method was tested for the measurement sections with the recorded sound signal and aural qualification of the CAN intensity.
4
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Artificial Intelligence and Learning Systems Methods in Supporting Long-Term Acoustic Climate Monitoring

100%
Kłaczyński M., Wszołek T.
Acta Physica Polonica A
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2013
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vol. 123
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issue 6
1024-1028
EN
Developing effective methods for automatic identification of noise sources is currently one of the most important tasks in long-term acoustical climate monitoring of the environment. Manual verification of recorded data, when it comes to proper determination of noise levels, is time-consuming and costly. A possible solution is to use pattern recognition techniques for acoustic signal recorded by a monitoring station. This paper presents usefulness of special directed measurement techniques, acoustic signal processing, and classification methods using artificial intelligence (the Sammon mapping) and learning systems methods (Support Vector Machines) in the recognition of corona audible noise from ultra-high voltage AC transmission lines.
5
Content available remote

Variability Influence of Input Parameters οn Result of Room Acoustic Calculation

100%
Mleczko D., Wszołek T.
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issue 1
128-130
EN
For a long time there is a need in industry of acoustical modeling of rooms. Modeling is necessary for new production room design, the exchange of existing machinery, modernization or expansion of production rooms, changes in production profile or acoustical room adaptation for acoustical work conditions improvement. in such cases modeling quality is essential and thanks to uncertainty analysis it is possible to quantitatively estimate the effect that input parameters value variation has on model behavior. The article presents general rules for sound pressure level prediction uncertainty calculation in a room. By partial uncertainty calculation analysis of input parameters influence on uncertainty prediction an effort was taken to find parameters with biggest influence on the prediction process. As an example an industrial production room is presented which was modeled to predict noise level on a work stands after it was expanded.
6
Content available remote

On Certain Problems Concerning Environmental Impact Assessment of Wind Turbines in Scope of Acoustic Effects

81%
Wszołek T., Kłaczyński M., Mleczko D., Ozga A.
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vol. 125
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issue 4A
A-38-A-44
EN
The paper deals with difficulties that are encountered by investors and decision-making authorities in the course of investment processes involving construction of wind power plants. Moreover, attention is focused on absence of standardized procedures that could be used to determine environmental impact of wind turbines, mainly in the scope of acoustic effects appearing in conditions typical for operation of such devices (strong wind), high elevation of related noise sources, and the nature of the sound emission (tonality and amplitude modulation). Lack of such procedures is a source of serious ambiguities developing in assessment of all investment stages - planning and forecasting, construction, and operation. An additional problem arises in the case of power plants located in the vicinity of Natura 2000 area, where construction projects are often obstructed on the grounds of unclear criteria concerning, among other things, the effect of acoustic phenomena on birds, bats, and other animals. It follows from the research presented in this paper that the consistent system of procedures and criteria should be worked out on the grounds of long-term monitoring studies.
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