Comparison of Microphone Traverse and Microphone Array for Determining Space Average Sound Pressure Level in a Reverberation Room

1976 ◽  
Vol 7 (2) ◽  
pp. 64 ◽  
Author(s):  
Curtis I. Holmer ◽  
David Lubman
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Microphone Array ◽  
Pressure Level

scholarly journals Experimental and Computational Methods for Investigating Automotive Door Closure Sounds

2018 ◽  
Author(s):  
Giuseppe T. V. Garro ◽  
Chris K. Mechefske
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Microphone Array ◽  
Pressure Level ◽  
Rigid Body Dynamic ◽  
Frequency Decomposition ◽  
Depth Analysis ◽  
Level Versus ◽  
Reaction Forces ◽  
Explicit Dynamic

The focus of this investigation was to examine the acoustic trends present during operation of an automotive door closure at two impact speeds through experimental methods. Transient sound pressure of five different door closure mechanisms were collected in a semi-anechoic chamber using a three-element condenser microphone array. Post-processing methodologies such as Sound Pressure Level versus 1/3 Octave band and Continuous Wavelet Transform computations were conducted. These procedures provided an in-depth analysis on the overall generated sound in addition to identifying which frequencies dominate the response at specific impact events during latch operation. Computational model analyses of the closure system using Rigid Body Dynamic and Explicit Dynamic methods using ANSYS to obtain a clearer understanding of the latch component interactions. Recorded average sound pressure level, frequency decomposition, and impact reaction forces are presented in addition to the notable trends between both impacting speeds.

DETERMINATION OF MONOPOLE AND DIPOLE SOURCES OF FLOW AROUND A CYLINDER USING A VIRTUAL MICROPHONE ARRAY

Akustika ◽  
2021 ◽  
pp. 76
Author(s):  
Victor Ershov ◽  
Igor Khramtsov ◽  
Oleg Kustov
Keyword(s):  
Numerical Simulation ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Microphone Array ◽  
Pressure Level ◽  
Noise Sources ◽  
Ansys Fluent ◽  
Flow Around A Cylinder ◽  
Vortex Shedding Frequency

In this paper, the problem of localization of noise sources of flow around a cylinder was considered on the basis of a computational experiment using a virtual 54-channel microphone array. Numerical simulation was performed using the computational fluid dynamics software ANSYS Fluent. Several spatial orientations of the cylinder were considered for the generation of dipoles with different directions. Simulation of a simplified two-microphone azimuthal decomposition technique (ADT) is performed to determine the sound pressure level of the generated dipoles at a vortex shedding frequency of 1450 Hz. A procedure of localization of the noise of the flow around a virtual cylinder was performed using monopole and dipole beamforming algorithms. It was found that the numerical simulation results are in good agreement with the data obtained by other researchers, both in terms of the sound pressure level and the results of the localization of dipoles in space.

Analysis of an automobile door closure vibroacoustic response

2020 ◽  
pp. 107754632093200
Author(s):  
Giuseppe TV Garro ◽  
Braden T Warwick ◽  
Chris K Mechefske
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Microphone Array ◽  
Pressure Level ◽  
Acoustic Response ◽  
Element Analysis ◽  
Value Evaluation ◽  
Depth Analysis ◽  
Level Versus ◽  
Primary Impact

The acoustic response of a car door latch has been shown to directly impact the customers’ perceived quality and value evaluation of the automobile. This work introduces an experimentally validated computational model of three door latch components. The transient sound pressure level response of the three door latch components during door closure was collected in a semianechoic chamber using a three-element condenser microphone array. Postprocessing methodologies such as sound pressure level versus 1/3 octave band and continuous wavelet transform analysis were performed. This provided an in-depth analysis on the overall acoustic response and identification of dominant frequencies corresponding to four specific impact events during latch operation. Computational finite element analysis of the closure system using a rigid body, and explicit dynamic and transient structural acoustic analyses provided additional insights into the latch component interactions and the acoustic response generated empirically. Recorded average sound pressure level, frequency decomposition, and impact reaction forces are presented in addition to a comparison between the acoustic response for two different door closure speeds. It was found that an increased door closure speed increased the response sound pressure level, decreased damping of the primary impact, and decreased the frequency bandwidth of the response, thereby generating an acoustic response that would be perceived as noisier, less safe, and less secure by customers. These findings provide additional insights into the primary impact acoustic response of an automotive door latch during closure. The methodology introduced in this work allows automotive engineers to perform future work with modified latch components to further improve the psychoacoustic response of the automotive car door latch, further increasing the value evaluation of the automobile.

Contributions of Voice and Nonverbal Communication to Perceived Masculinity–Femininity for Cisgender and Transgender Communicators

2020 ◽  
Vol 63 (4) ◽  
pp. 931-947
Author(s):  
Teresa L. D. Hardy ◽  
Carol A. Boliek ◽  
Daniel Aalto ◽  
Justin Lewicke ◽  
Kristopher Wells ◽  
...  
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Vocal Tract ◽  
Presentation Mode ◽  
Pressure Level ◽  
Presentation Modes ◽  
Audiovisual Stimuli ◽  
Vocal Tract Resonance ◽  
Point Light

Purpose The purpose of this study was twofold: (a) to identify a set of communication-based predictors (including both acoustic and gestural variables) of masculinity–femininity ratings and (b) to explore differences in ratings between audio and audiovisual presentation modes for transgender and cisgender communicators. Method The voices and gestures of a group of cisgender men and women ( n = 10 of each) and transgender women ( n = 20) communicators were recorded while they recounted the story of a cartoon using acoustic and motion capture recording systems. A total of 17 acoustic and gestural variables were measured from these recordings. A group of observers ( n = 20) rated each communicator's masculinity–femininity based on 30- to 45-s samples of the cartoon description presented in three modes: audio, visual, and audio visual. Visual and audiovisual stimuli contained point light displays standardized for size. Ratings were made using a direct magnitude estimation scale without modulus. Communication-based predictors of masculinity–femininity ratings were identified using multiple regression, and analysis of variance was used to determine the effect of presentation mode on perceptual ratings. Results Fundamental frequency, average vowel formant, and sound pressure level were identified as significant predictors of masculinity–femininity ratings for these communicators. Communicators were rated significantly more feminine in the audio than the audiovisual mode and unreliably in the visual-only mode. Conclusions Both study purposes were met. Results support continued emphasis on fundamental frequency and vocal tract resonance in voice and communication modification training with transgender individuals and provide evidence for the potential benefit of modifying sound pressure level, especially when a masculine presentation is desired.

Case study: Theoretical calculation model and variable condition analysis research on the water-splashing noise for natural draft wet cooling towers

2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun
Keyword(s):  
Theoretical Model ◽  
Sound Pressure Level ◽  
Water Droplet ◽  
Water Distribution ◽  
Sound Pressure ◽  
Cooling Tower ◽  
Distribution Patterns ◽  
Calculation Model ◽  
Pressure Level ◽  
Cooling Towers

Based on the basic theory of water droplets impact noise, the generation mechanism and calculation model of the water-splashing noise for natural draft wet cooling towers were established in this study, and then by means of the custom software, the water-splashing noise was studied under different water droplet diameters and water-spraying densities as well as partition water distribution patterns conditions. Comparedwith the water-splashing noise of the field test, the average difference of the theoretical and the measured value is 0.82 dB, which validates the accuracy of the established theoretical model. The results based on theoretical model showed that, when the water droplet diameters are smaller in cooling tower, the attenuation of total sound pressure level of the water-splashing noise is greater. From 0 m to 8 m away from the cooling tower, the sound pressure level of the watersplashing noise of 3 mm and 6 mm water droplets decreases by 8.20 dB and 4.36 dB, respectively. Additionally, when the water-spraying density becomes twice of the designed value, the sound pressure level of water-splashing noise all increases by 3.01 dB for the cooling towers of 300 MW, 600 MW and 1000 MW units. Finally, under the partition water distribution patterns, the change of the sound pressure level is small. For the R s/2 and Rs/3 partition radius (Rs is the radius of water-spraying area), when the water-spraying density ratio between the outer and inner zone increases from 1 to 3, the sound pressure level of water-splashing noise increases by 0.7 dB and 0.3 dB, respectively.

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