Loudness level versus sound‐pressure level: A comparison of musical instruments

1994 ◽  
Vol 96 (6) ◽  
pp. 3375-3379 ◽  
Author(s):  
Andrzej Miśkiewicz ◽  
Andrzej Rakowski
Author(s):  
Giuseppe T. V. Garro ◽  
Chris K. Mechefske

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.


2006 ◽  
Vol 67 (7) ◽  
pp. 720-730 ◽  
Author(s):  
Mutsumi Ishibashi ◽  
Anna Preis ◽  
Fumiaki Satoh ◽  
Hideki Tachibana

2020 ◽  
pp. 107754632093200
Author(s):  
Giuseppe TV Garro ◽  
Braden T Warwick ◽  
Chris K Mechefske

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.


2020 ◽  
Vol 63 (4) ◽  
pp. 931-947
Author(s):  
Teresa L. D. Hardy ◽  
Carol A. Boliek ◽  
Daniel Aalto ◽  
Justin Lewicke ◽  
Kristopher Wells ◽  
...  

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.


2020 ◽  
Vol 68 (2) ◽  
pp. 137-145
Author(s):  
Yang Zhouo ◽  
Ming Gao ◽  
Suoying He ◽  
Yuetao Shi ◽  
Fengzhong Sun

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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