scholarly journals Subjective Evaluation of Stage Acoustics with the Alteration of the Sound Pressure Level of Reverberation

2017 ◽  
Vol 27 (2) ◽  
pp. 129-138
Author(s):  
Youngsun Kim ◽  
Jeongho Jeong ◽  
Jinyong Jeon
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Subjective Evaluation ◽  
Pressure Level

Just noticeable difference of sound pressure level of speech in open-plan office

2021 ◽  
Vol 263 (1) ◽  
pp. 5166-5169
Author(s):  
Haram Lee ◽  
Hyunin Jo ◽  
Jin Yong Jeon
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Paired Comparison ◽  
Subjective Evaluation ◽  
Simulation Models ◽  
Pressure Level ◽  
Just Noticeable Difference ◽  
Sound Sources ◽  
Sound Environment ◽  
Open Plan

In this study, the general sound environment characteristics of open-plan office (OPO) were investigated, and just noticeable difference (JND) of sound pressure level of speech at a distance of 4 m (Lp,A,S,4m) suggested in ISO 3382-3 was suggested. First, in order to understand the sound environment characteristics of OPO, one minute sound sources recorded in 8 offices were collected and physical and psychological acoustic characteristics were analyzed. A total of 30 office workers were subject to subjective evaluation on 8 sound sources, and they were asked to respond to questionnaires related to annoyance, work satisfaction, and speech privacy. Next, to investigate the JND, two computer simulation models identical to those of the actual OPO were implemented, and sound sources each having six different Lp,A,S,4m values were generated through the change of the sound absorption coefficient of the interior finish. The JND of Lp,A,S,4m was presented by performing paired comparison for the same subjects. It is expected that the JND of Lp,A,S,4m proposed in this study can be used for the sound environment rating of OPO.

scholarly journals Evaluation and Improvement of the Sound Quality of a Diesel Engine Based on Tests and Simulations

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 777 ◽  
Author(s):  
Zhengwei Yang ◽  
Huihua Feng ◽  
Bingjie Ma ◽  
Ammar Abdualrahim Alnor Khalifa
Keyword(s):  
Diesel Engine ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Subjective Evaluation ◽  
Sound Field ◽  
Sound Quality ◽  
Pressure Level ◽  
Sound Power ◽  
Improvement Strategy ◽  
Radiated Sound

Traditional acoustic evaluation of a diesel engine generally uses the A-weighted sound pressure level (AWSPL) and radiated sound power to assess the noise of an engine prototype present in an experiment. However, this cannot accurately and comprehensively reflect the auditory senses of human subjects during the simulation stage. To overcome such shortage, the Moore–Glasberg loudness and sharpness approach is applied to evaluate and improve the sound quality (SQ) of a 16 V-type marine diesel engine, and synthesizing noise audio files. Through finite element (FE) simulations, the modes of the engine’s block and the average vibrational velocity of the entire engine surface were calculated and compared with the test results. By further applying an automatically matched layer (AML) approach, the engine-radiated sound pressure level (SPL) and sound power contributions of all engine parts were obtained. By analyzing the Moore–Glasberg loudness and sharpness characteristics of three critical sound field points, an improvement strategy of the oil sump was then proposed. After improvement, both the loudness and sharpness decreased significantly. To verify the objective SQ evaluation results, ten noise audio clips of the diesel engine were then synthesized and tested. The subjective evaluation results were in accordance with the simulated analysis. Therefore, the proposed approach to analyze and improve the SQ of a diesel engine is reliable and effective.

Application of Dynamic Vibration Absorber in Noise Control of Whole Vehicle

2012 ◽  
Vol 226-228 ◽  
pp. 423-426
Author(s):  
Xue Ying Xu ◽  
Guo Hua Han ◽  
Zha Gen Ma
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Subjective Evaluation ◽  
Internal Noise ◽  
Pressure Level ◽  
Vibration Absorber ◽  
Frequency Noise ◽  
Dynamic Vibration Absorber ◽  
Engine Mounts ◽  
Dynamic Vibration

As cars become quieter the sound quality of components becomes more critical in the customer perception of car quality. Considering that middle frequency noise plays an important roll for internal noise, the noise signals in the range from200Hz to 500Hz are specially emphasized. Then the acoustic evaluation parameters, such as Sound Pressure Level, Acceleration have been evaluated. Judged from experiences and measuring results, an abnormal noise comes from engine mounts, through the use of dynamic vibration absorber on engine mounts, Vibration on engine mounts and Sound Pressure Level in interior vehicle were greatly improved. At the same time, subjective evaluation also indicated that there was no complaint any more in passenger compartment. Dynamic vibration absorber can properly solve the abnormal noise.

The Study on Influence of High Frequency Noise on Sound Quality for Generator

2011 ◽  
Vol 105-107 ◽  
pp. 74-79
Author(s):  
Zha Gen Ma ◽  
Xue Ying Xu ◽  
Guo Hua Han
Keyword(s):  
Sound Pressure Level ◽  
High Frequency ◽  
Sound Pressure ◽  
Evaluation Method ◽  
Subjective Evaluation ◽  
Internal Noise ◽  
Sound Quality ◽  
Pressure Level ◽  
Frequency Noise ◽  
High Frequency Noise

As cars become quieter the sound quality of components becomes more critical in the customer perception of car quality. This requires a need of new evaluation method for the specification of component sounds. Considering that high frequency noise plays an important roll for internal noise, the noise signals in the range from 7000Hz to 8000Hz are specially emphasized. Then the acoustic evaluation parameters, such as Sound Pressure Level, Sharpness and Steadiness have been evaluated. Judged from experiences and measuring results, an abnormal noise comes from Generator, through the exchange of Generator, Sound Pressure Level and sharpness were greatly improved. At the same time, subjective evaluation also indicated that there was no complaint any more in passenger compartment. Low Sound Pressure Level, sharpness can lead to perceived high product quality.

The Study of Sound Quality for Car Compressor

2012 ◽  
Vol 226-228 ◽  
pp. 444-447 ◽  
Author(s):  
Yan Fang Hou ◽  
Guo Hua Han ◽  
Xue Ying Xu
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Evaluation Method ◽  
Subjective Evaluation ◽  
Objective Evaluation ◽  
Sound Quality ◽  
Pressure Level ◽  
Subjective Perception ◽  
Problem Frequency ◽  
Psychoacoustic Metrics

As cars become more and more quiet the sound quality of rotary components such as car compressor becomes more important in the customer’s subjective perception of passenger car quality. This needs a new evaluation method which is not only the traditional method like sound pressure level but also Psychoacoustic Metrics to focus the specification of component sounds. This paper on one hand analyzed one car’s abnormal noise reason through the tests, found the main problem frequency band of the compressor, and on the other hand studied the compressor’s psychoacoustic metrics. In this paper the countermeasure of solving this problem was also given, and then noise level and psychoacoustic parameters are compared. Both objective evaluation and subjective evaluation showed that the compressor with the solution not only reduced the sound pressure level, but also improved the car sound quality greatly.

Nonlinear modeling and prediction of forklift acoustic annoyance based on the improved neural networks

SIMULATION ◽  
2021 ◽  
pp. 003754972110648
Author(s):  
Enlai Zhang ◽  
Jiading Lian ◽  
Jingjing Zhang ◽  
Jiahe Lin
Keyword(s):  
Neural Network ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Evaluation Method ◽  
Comprehensive Evaluation ◽  
Nonlinear Modeling ◽  
Subjective Evaluation ◽  
Pressure Level ◽  
Subjective Perception ◽  
Artificial Neural Network Ann

Aiming at the characteristics of high decibels and multiple samples for forklift noise, a subjective evaluation method of rank score comparison (RSC) based on annoyance is presented. After pre-evaluation, comprehensive evaluation and data tests on collected 50 noise samples, the annoyance grades of all noise samples were obtained, and seven psycho-acoustic parameters including linear sound pressure level (LSPL), A-weighted sound pressure level (ASPL), loudness, sharpness, roughness, impulsiveness and articulation index (AI) were determined by correlation calculation. Considering the nonlinear characteristics of human ear subjective perception, objective parameters, and annoyance were used as input and output variables correspondingly and then three nonlinear mathematical models of forklift acoustic annoyance were established using traditional artificial neural network (ANN), genetic-algorithm neural network (GANN), and particle-swarm-optimization neural network (PSONN). Moreover, the prediction accuracy of the three models was tested and compared by sample data. The results indicate that the average relative error (ARE) between the experimental and predicted values of acoustic annoyance based on PSONN model is 3.893%, which provides an effective technical support for further optimization and subjective evaluation.

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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