Wyniki wyszukiwania - Biblioteka Nauki

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Acoustic Study of REpower MM92 Wind Turbines During Exploitation

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Kłaczyński M. , Wszołek T.

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tom Vol. 39, No. 1

3--10

EN

The paper presents the current state of knowledge concerning the sources of noise generated by wind turbines, force measurement methodology, and assessment of noise onerousness in this type of installation, on the basis of a study concerning a wind farm with five REpower MM92 wind turbines and the electric power of 2 MW and the sound power level of 104.2 dB(A) each. Particular attention was focused on the often discussed problem of presence of infrasound generated by turbines and on the requirements of the applicable reference methodologies for the measurement of wind speed to 5 m/s, while the turbine reaches its full power at speeds above 10 m/s.

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A Vibroacoustic Model of Selected Human Larynx Diseases

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Engel Z. W. , Kłaczyński M. , Wszołek W.

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tom Vol. 13, No. 4

367--379

EN

With the present development of digital registration and methods for processing speech it is possible to make effective objective acoustic diagnostics for medical purposes. These methods are useful as all pathologies and diseases of the human vocal tract influence the quality of a patient’s speech signal. Diagnostics of the voice organ can be defined as an unambiguous recognition of the current condition of a specific voice source. Such recognition is based on an evaluation of essential acoustic parameters of the speech signal. This requires creating a vibroacoustic model of selected deformations of Polish speech in relation to specific human larynx diseases. An analysis of speech and parameter mapping in 29-dimensional space is reviewed in this study. Speech parameters were extracted in time, frequency and cepstral (quefrency) domains resulting in diagrams that qualified symptoms and conditions of selected human larynx diseases. The paper presents graphically selected human larynx diseases.

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Nuisance assessment of different annoying sounds based on psychoacoustic metrics and electroencephalography

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Pamuła H. , Kasprzak C. , Kłaczyński M.

Diagnostyka

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2016

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tom Vol. 17, No. 3

67--74

EN

The aim of the study was to assess whether four psychoacoustic parameters (sharpness, roughness, fluctuation strength and tonality) are useful in describing the perceived annoyance of selected noise sources with respect to an objective assessment based on the acoustics standards. Second goal was to verify if the perceived annoyance of such noises correlates with dominant frequency in electroencephalography (EEG) frequency bands. Twenty sound sources, varying in the degree of nuisance, have been assessed by 178 respondents in an Internet-based psychoacoustic test. Obtained annoyance grades were correlated with calculated psychoacoustic and normative parameters and the positive correlation between perceived annoyance and three psychoacoustic parameters (sharpness, roughness and fluctuation strength) was found. In the second part EEG study during listening of recorded sounds was performed on 18 healthy volunteers. Spearman’s rank correlation confirmed that dominant frequencies in alpha (7-14 Hz) and beta2 band (20-30 Hz) were rising with the increasing annoyance of the sounds. Results obtained may be useful in specifying and clarifying permissible noise levels for annoying sounds.

PL

Celem prac było zbadanie czy psychoakustyczne parametry takie jak ostrość, szorstkość, siła fluktuacji, tonalność mogą być użyteczne do opisu uciążliwości wybranych źródeł hałasu, w odniesieniu do obiektywnej oceny opartej o akustyczne standardy. Drugim celem pracy było sprawdzenie, czy postrzegana uciążliwość tych dźwięków koreluje z częstotliwościami dominującymi w pasmach częstotliwości stosowanych w elektroencefalografii (EEG). W pierwszej części badań 178 osób wypełniło ankietę, oceniając uciążliwość prezentowanych dźwięków. Otrzymane oceny zostały skorelowane z wyliczonymi psychoakustycznymi i normatywnymi parametrami. Potwierdzono, że wraz ze wzrostem wartości parametrów takich jak ostrość, szorstkość i siła fluktuacji, wzrasta także postrzegana przez słuchaczy uciążliwość dźwięków. W drugiej części eksperymentu wykonano badania EEG 18 osób podczas odsłuchu powyższych 20 nagrań. Test korelacji rang Spearmana potwierdził, że dominujące częstotliwości w paśmie alfa (7-14Hz) i beta2 (20-30Hz) wzrastały wraz ze wzrostem średniej oceny uciążliwości. Wyniki przeprowadzonych badań mogą być przydatne do doprecyzowania parametrów oceny hałasu i ich dopuszczalnych wartości.