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Wyszukujesz frazę "sound source" wg kryterium: Temat


Tytuł:
Design Sensitivity Studies on a Hydroacoustic Projector Using an Experimentally Validated Easy-to-Build Model
Autorzy:
Sreejith, Vattaparambil Sreedharan
Tiwari, Nachiketa
Powiązania:
https://bibliotekanauki.pl/articles/2141678.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
low frequency sound source
underwater transducer
fluid power
hydro-electro-mechano-acoustic analogy
hydraulic valve
piston
cylinder
Opis:
Hydroacoustic projectors are useful for generating low frequency sounds in water. Existing works on hydroacoustic projectors require two significant enhancements, especially for designers. First, we need to understand the influence of important projector design parameters on its performance. Such insights can be very useful in developing a compact and efficient projector. Second, there is a need for an integrated model of the projector based on easily available and user-friendly numerical tools which do not require development of complex customised mathematical analogs of projector components. The present work addresses both such needs. Towards these goals, an experimentally validated, easy-to-build projector model was developed and used to conduct design sensitivity studies. We show that reductions in pipe compliance and air content in oil, and an increase in orifice discharge coefficient can yield remarkable improvements in projector’s SPL. We also show that reductions in pipe length and cylinder diameter cause moderate improvements in performance in mass and stiffness controlled regions, respectively. In contrast, the projector performance is insensitive to changes in pistonic mass, cylinder length, and diaphragm stiffness. Finally, we report that while pipe compliance and air content in oil can sharply alter system resonance, the effects of changes in pipe length and pistonic mass on it are moderate in nature.
Źródło:
Archives of Acoustics; 2022, 47, 1; 113-124
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microphone Based Acoustic Vector Sensor for Direction Finding with Bias Removal
Autorzy:
Wajid, Mohd
Kumar, Arun
Bahl, Rajendar
Powiązania:
https://bibliotekanauki.pl/articles/2141636.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic measurements
acoustic sensor
acoustic vector sensor
direction-of-arrival estimation
finite element analysis
microphones
particle velocity
sound source localization
Opis:
The acoustic vector sensor (AVS) is used to measure the acoustic intensity, which gives the direction-of-arrival (DOA) of an acoustic source. However, while estimating the DOA from the measured acoustic intensity the finite microphone separation (d) in a practical AVS causes angular bias. Also, in the presence of noise there exists a trade off between the bias (strictly increasing function of d) and variance (strictly decreasing function of d) of the DOA estimate. In this paper, we propose a novel method for mitigating the angular bias caused due to finite microphone separation in an AVS. We have reduced the variance by increasing the microphone separation and then removed the bias with the proposed bias model. Our approach employs the finite element method (FEM) and curves fitting to model the angular bias in terms of microphone separations and frequency of a narrowband signal. Further, the bias correction algorithm based on the intensity spectrum has been proposed to improve the DOA estimation accuracy of a broadband signal. Simulation results demonstrate that the proposed bias correction scheme significantly reduces the angular bias and improves the root mean square angular error (RMSAE) in the presence of noise. Experiments have been performed in an acoustic full anechoic room to corroborate the effect of microphone separation on DOA estimation and the efficacy of the bias correction method.
Źródło:
Archives of Acoustics; 2022, 47, 2; 151-167
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinig of the sound power of the fan in in situ conditions using the virtual reference source method
Autorzy:
Suder-Dębska, Katarzyna
Czajka, Ireneusz
Łojek, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2146654.pdf
Data publikacji:
2021
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
fan as a sound source
sound power
noise
reference source
regularization
wentylator jako źródło dźwięku
moc akustyczna
hałas
źródło odniesienia
regularyzacja
Opis:
Sound power is one of the basic parameters characterizing the sound source and has a direct impact on the acoustic climate in its surroundings. Therefore, the determining of the sound power of machines is a practical problem. While there are many methods of determining the sound power, each of them has its own limitations. The authors presented the implementation of a comparative method of determining the sound power with the use of a virtual reference source. The method was used to test a high-efficiency flue gas exhaust fan installed on a laboratory stand. The sound source was placed in the geometric centre of the fan and the acoustic field distribution in the room was determined using geometrical methods. After determining the influence factors, the value of the source sound power of the source was calculated by means of the Moore-Penrose pseudo-inverse. Since the problem under study belongs to the inverse problems, the Tikhonov regularization was used, where the value of the parameter α was determined by the L-curve method.
Źródło:
Vibrations in Physical Systems; 2021, 32, 2; art. no. 2021206
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Error Analysis of Sound Source Directivity Interpolation Based on Spherical Harmonics
Autorzy:
Szwajcowski, Adam
Krause, Daniel
Snakowska, Anna
Powiązania:
https://bibliotekanauki.pl/articles/1953503.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound source directivity
spherical harmonics
interpolation error
sparse measurements
Opis:
Precise measurement of the sound source directivity not only requires special equipment, but also is time-consuming. Alternatively, one can reduce the number of measurement points and apply spatial interpolation to retrieve a high-resolution approximation of directivity function. This paper discusses the interpolation error for different algorithms with emphasis on the one based on spherical harmonics. The analysis is performed on raw directivity data for two loudspeaker systems. The directivity was measured using sampling schemes of different densities and point distributions (equiangular and equiareal). Then, the results were interpolated and compared with these obtained on the standard 5° regular grid. The application of the spherical harmonic approximation to sparse measurement data yields a mean error of less than 1 dB with the number of measurement points being reduced by 89%. The impact of the sparse grid type on the retrieval error is also discussed. The presented results facilitate optimal sampling grid choice for low-resolution directivity measurements.
Źródło:
Archives of Acoustics; 2021, 46, 1; 95-104
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Combination of Spectrum Subtraction and Cross-power Spectrum Phase Method for Time Delay Estimation
Autorzy:
Bin, Feng
Lei, Xu
Powiązania:
https://bibliotekanauki.pl/articles/177562.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sound source localization
time delay estimation
generalized cross correlation
phase of cross power spectrum
spectral subtraction
Opis:
In order to solve the problem of large error of delay estimation in low SNR environment, a new delay estimation method based on cross power spectral frequency domain weighting and spectrum subtraction is proposed. Through theoretical analysis and MATLAB simulation, among the four common weighting functions, it is proved that the cross-power spectral phase weighting method has a good sharpening effect on the peak value of the cross-correlation function, and it is verified that the improved spectral subtraction method generally has a good noise reduction effect under different SNR environments. Finally, the joint simulation results of the whole algorithm show that the combination of spectrum subtraction and cross-power spectrum phase method can effectively sharpen the peak value of cross-correlation function and improve the accuracy of time delay estimation in the low SNR environment. The results of this paper can provide useful help for sound source localization in complex environments.
Źródło:
Archives of Acoustics; 2020, 45, 3; 453-458
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Localization of noise sources in electric cookers based on sound pressure and intensity measurements
Autorzy:
Jakubek, Bartosz
Barczewski, Roman
Tabaszewski, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/127684.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
electric cooker
acoustic pressure
sound intensity
noise source localization
kuchenka elektryczna
ciśnienie akustyczne
natężenie dźwięku
lokalizacja źródeł hałasu
Opis:
The main aim of the study was to compare the features of acoustic maps created on the basis of measurements of sound pressure and intensity in a near acoustic field. Data for comparisons were obtained within the framework of acoustic tests of electric cookers. The results of these studies may help in the selection of acoustic mapping and optimization methods according to individual needs and/or requirements concerning selectivity, measurement bandwidth, dynamics and the ability to locate sound-emitting areas. The paper also presents the results of the spectral analysis of the dominant sources of noise in the cooker, which was helpful in identifying and locating paths of noise propagation from the inside of the cooker.
Źródło:
Vibrations in Physical Systems; 2019, 30, 2; 1-14
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of Sound Power Levels and Surface Absorption Coefficients in Multi-Source Industrial Buildings by Using a Simplified Diffusion Model
Autorzy:
Sequeira, M. E.
Cortínez, V. H.
Powiązania:
https://bibliotekanauki.pl/articles/177679.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
industrial noise
noise source identification
sound absorption coefficient
two-dimensional acoustic diffusion model
simulated annealing algorithm
Opis:
This article deals with the identification of sound powers and absorption surface coefficients in multisource industrial buildings from the knowledge of the sound pressure levels (SPLs) at several monitoring points. This inverse problem is formulated as one of optimisation in which the objective function is the difference between the measured and predicted SPLs. The methodology combines the use of a simplified acoustic diffusion model with the simulated annealing optimisation technique. The former is a recently developed model for estimating the SPLs in a fast and sufficiently accurate form. The low computational cost of the model constitutes the major advantage for the optimisation procedure due to the great numer of simulations required. Numerical examples are given to show the efficiency of the proposed approach.
Źródło:
Archives of Acoustics; 2018, 43, 1; 93-102
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of muscle tone on the development of auditory perception – research orientation
Autorzy:
Pawlukowska, Wioletta
Siwczak, Katarzyna
Szylińska, Aleksandra
Turoń, Agnieszka
Rotter, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/552400.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Przyjaciół Medycyny Rodzinnej i Lekarzy Rodzinnych
Tematy:
directional hearing, auditory perception, sound source localization, delayed motor development,
proper motor development.
Źródło:
Family Medicine & Primary Care Review; 2017, 4; 382-386
1734-3402
Pojawia się w:
Family Medicine & Primary Care Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traffic Noise Models for Curved Roads
Autorzy:
Popescu, D. I.
Cosma, I.
Powiązania:
https://bibliotekanauki.pl/articles/176976.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic noise
noise source modelling
sound field
curved road
Opis:
The paper presents two theoretical models for traffic noise level distribution on curved horizontal roads. In the case of vehicles moving on a given route, one can consider, in terms of sound field, that the granular traffic is equivalent for short periods with a quasi-continuous noise flow. When computing and modelling the noise level generated by traffic on roads with complex trajectory, it is common to treat the route as a sum of small length road segments, each being assimilated with a linear noise source. This paper started from the assumption that the route can be decomposed into a sequence of linear and arc-shaped road segments, each of which is treated as a linear respectively curved noise source. An arc-shaped road segment is modelled by a tubular vibrating surface, of circular or rectangular section. In the case of rectangular section, the vibrating blade emits complex sounds on its both vertical sides and the generated sound field can be described more clearly, qualitatively and quantitatively, through intensity distribution. The theoretical models presented in the paper have direct application to the traffic noise prediction and noise maps drawing.
Źródło:
Archives of Acoustics; 2016, 41, 2; 309-314
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Metody wyznaczania poziomu mocy akustycznej źródła
Methods for determining the sound power level of a noise source
Autorzy:
Nolepa, A.
Kiprian, K.
Siemiątkowski, G.
Łach, P.
Powiązania:
https://bibliotekanauki.pl/articles/392342.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
hałas
źródło hałasu
moc akustyczna
metoda badań
dokładność
procedura badawcza
wymagania normowe
warunki pomiaru
ciśnienie akustyczne
poziom dźwięku
noise
noise source
sound power
test method
accuracy
test procedure
standard requirements
measurement conditions
acoustic pressure
sound level
Opis:
Podstawowym dokumentem regulującym procedury wyznaczania mocy akustycznej jest PN-EN ISO 3740: 2003 – Akustyka. Wyznaczanie poziomów mocy akustycznej źródeł hałasu. Wytyczne stosowania norm podstawowych. W normie tej przedstawiono wytyczne do stosowania serii norm międzynarodowych ISO 3740 i ISO 9614 opisujących wiele metod wyznaczania mocy akustycznej różnych typów maszyn i urządzeń. Zalecaną klasą dokładności dla celów deklarowania hałasu jest klasa dokładności technicznej, tj. klasa dokładności 2. Do badań wytypowano dwie normy PN-EN ISO 3744 oraz PN-EN ISO 3746. Norma PN-EN ISO 3744 spełnia wymagania 2 klasy dokładności, natomiast norma PN-EN ISO 3746 spełnia wymagania 3 klasy dokładności. W artykule opisano i porównano wymagania obydwu norm. Wykonano badania 9 źródeł hałasu zgodnie z normą PN-EN ISO 3744 i wyznaczono dla nich moce akustyczne. Przeprowadzono analizę spełnienia wymagań zawartych w normie PN-EN ISO 3744 wykorzystanej do badań. Wszystkie wymagania zostały spełnione, w związku z czym można było uznać wyniki badań jako wykonane z 2 klasą dokładności.
The basic document regulating procedures of determination of sound power is a polish standard no. PN-EN ISO 3740 called – Acoustics. Determination of sound power levels of noise source. Guidelines for the use of basic standards – which was published in October 2003. In this standard the guidelines for the use of international standards ISO 3740 and ISO 9614 were presented, which describe different methods of determining the sound power for machinery and equipment of various types. Favoured accuracy class for the purposes of noise declaration is technical accuracy class, i.e. 2. accuracy class. Two standards PN-EN ISO 3744 and PN-EN ISO 3746 were chosen for research. PN-EN ISO 3744 meets requirements 2. accuracy class and PN-EN ISO 3746 meets requirements 3. accuracy class. In this paper the requirements of two standards were described and compared. The research of 9 noise sources according to PN-EN ISO 3744 standard were performed and the sound powers were determined for these sources. The analysis of the requirements used in this standard was performed. All the requirements were met therefore the research results were accepted as performed according to the accuracy class 2.
Źródło:
Prace Instytutu Ceramiki i Materiałów Budowlanych; 2015, R. 8, nr 21, 21; 43-57
1899-3230
Pojawia się w:
Prace Instytutu Ceramiki i Materiałów Budowlanych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of infrasound generated in urban areas on health of people and animals - an attempt to localize environmental infrasound sources using computer simulations
Autorzy:
Nowicki, G.
Nowicki, T.J.
Prystupa, A.
Slusarska, B.
Chemperek, E.
Powiązania:
https://bibliotekanauki.pl/articles/3260.pdf
Data publikacji:
2014
Wydawca:
Instytut Medycyny Wsi
Tematy:
infrasound
low-frequency sound zob.infrasound
urban area
human health
health
people
animal health
environmental infrasound source
computer simulation
Opis:
Introduction. Inaudible but ubiquitous environmental infrasound undoubtedly affects the frame of mind and health of humans. Objective. The object of the study is to prove that civil engineering objects can be sources of infrasound, and a review of the literature on effects of infrasound on the health of people and animals. Methods. Computer simulation of an air flow around a typical element of outdoor infrastructure. The simulation was carried out using the author’s computer programme, based on Discrete Vortex Method algorithms. Results and conclusions. The numerical experiment clearly proved that industrial objects can be sources of infrasonic noise during windy weather. The picture of air flow around a cylinder shows that regular turbulent motion is a source of sound with one dominating frequency. The sound once generated propagate far from its source. Frequency and intensity of the sound depends on wind velocity and shape of the object. Further research in this area are advisable.
Źródło:
Journal of Pre-Clinical and Clinical Research; 2014, 08, 2
1898-2395
Pojawia się w:
Journal of Pre-Clinical and Clinical Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technical Notes : Practical Concerns Associated with Single-Number Ratings in Measuring Sound Transmission Loss Properties of Partition Panels
Autorzy:
Garg, N.
Kumar, A.
Maji, S.
Powiązania:
https://bibliotekanauki.pl/articles/177637.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Sound Transmission Loss
Sound Transmission Class
spectrum adaptation terms
ISO 717-1
weighted sound reduction index
spectrum adaptation term corresponding to noise source
Cx
TL
STC
Opis:
The paper presents an extensive review investigating the practical aspects related to the use of single- number ratings used in describing the sound insulation performance of partition wall panels and practical complications encountered in precise measurements in extensive frequency range from 50 Hz to 5 kHz. SWOT analysis of various single number ratings is described. A laboratory investigation on a double wall partition panel combination revealed the significant dependence of STC rating on transmission loss at 125 Hz attributed to 8 dB rule. An investigation conducted on devising alternative spectrums of aircraft noise, traffic noise, vehicular horn noise and elevated metro train noise as an extension to ISO 717-1 Ctr for ascertaining the sound insulation properties of materials exclusively towards these noise sources revealed that the single-number rating Rw + Ctr calculated using ISO 717-1 Ctr gives the minimum sound insulation, when compared with Rw + Cx calculated using the alternative spectrums of aircraft noise, traffic noise, etc., which means that material provides a higher sound insulation to the other noise sources. It is also observed that spectrum adaptation term Cx calculated using the spectrum of noise sources having high sound pressure levels in lower frequencies decreases as compared to ISO 717-1 Ctr owing to significant dependence of Ctr at lower frequencies.
Źródło:
Archives of Acoustics; 2013, 38, 1; 115-124
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-Channel System for Sound Creation in Open Areas
Autorzy:
Gołaś, A.
Suder-Dębska, K.
Powiązania:
https://bibliotekanauki.pl/articles/176685.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound creation system
open area
spatial impression
noise
geometrical method
inverse image source method
Opis:
There are typically two systems in use for sound reinforcement in open areas: the central, “wall of sound” system with speakers localized at the sides of the stage, and the zone system, in which additional speakers are introduced to obtain a uniform sound pressure level throughout the area of listening. In the past two decades the line array systems gained great popularity. The main purpose of their use is to obtain a uniformly distributed sound level throughout the listening area in order to achieve good speech intelligibility. The present paper aims to present an alternative and original method of sound reinforcement in open areas which is in contrast to the above solutions. This new method allows achieving a uniformly distributed sound pressure and good speech intelligibility in the area of interest, and also allows to gain spatial sound impression that accompanies sound reproduction in concert halls. Another advantage of the proposed system is the reduction of the sound level outside the area of interest, i.e. reduction of the noise level outside the area of listening.
Źródło:
Archives of Acoustics; 2012, 37, 3; 323-329
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Objectivization of Audio-Visual Correlation Analysis
Autorzy:
Kunka, B.
Kostek, B.
Powiązania:
https://bibliotekanauki.pl/articles/177202.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sound perception
sound source localization
virtual sound source shifting
bi-modal perception
cross-modal perception
image proximity effect
ventriloquism effect
visual attention
perceptual illusion
eye-gaze tracking
Opis:
Simultaneous perception of audio and visual stimuli often causes concealment or misrepresentation of information actually contained in these stimuli. Such effects are called the "image proximity effect" or the "ventriloquism effect" in the literature. Until recently, most research carried out to understand their nature was based on subjective assessments. The authors of this paper propose a methodology based on both subjective and objectively retrieved data. In this methodology, objective data reflect the screen areas that attract most attention. The data were collected and processed by an eye-gaze tracking system. To support the proposed methodology, two series of experiments were conducted – one with a commercial eye-gaze tracking system Tobii T60, and another with the Cyber-Eye system developed at the Multimedia Systems Department of the Gdańsk University of Technology. In most cases, the visual-auditory stimuli were presented using a 3D video. It was found that the eye-gaze tracking system did objectivize the results of experiments. Moreover, the tests revealed a strong correlation between the localization of a visual stimulus on which a participant’s gaze focused and the value of the "image proximity effect". It was also proved that gaze tracking may be useful in experiments which aim at evaluation of the proximity effect when presented visual stimuli are stereoscopic.
Źródło:
Archives of Acoustics; 2012, 37, 1; 63-72
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie holografii akustycznej w ocenie mocy wypromieniowanej przez mikropompę zębatą
Application of acoustic holography in assessing the power radiated by micro gear pump
Autorzy:
Osiński, P.
Powiązania:
https://bibliotekanauki.pl/articles/270003.pdf
Data publikacji:
2012
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
mikropompa zębata
holografia akustyczna
źródła dźwięku
lokalizacja
micro gear pump
acoustic holography
sound source
localization
Opis:
W artykule przedstawiono przykładowe wyniki badań akustycznych wykonanych dla mikropompy zębatej. Badania przeprowadzono z wykorzystaniem zestawu do holografii akustycznej. Wykorzystana aparatura pozwala na określenie wypromieniowanej mocy akustycznej oraz na przeprowadzenie lokalizacji źródeł dźwięku, bazując na algorytmie STSF przestrzennej transformacji pól dźwiękowych.
In article are examples of acoustic test results carried out on the microhydraulic gear pump. Testing was conducted using a set of sound to holography. Used apparatus allows definition of radiated sound power and to carry out the location of the sound sources based on algorithm STSF spatial transformation of sound fields.
Źródło:
Inżynieria Maszyn; 2012, R. 17, z. 4; 93-106
1426-708X
Pojawia się w:
Inżynieria Maszyn
Dostawca treści:
Biblioteka Nauki
Artykuł

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