Development of Method for Measurement Sound Pressure Level to Use Earphone

2013 ◽  
Vol 717 ◽  
pp. 378-383
Author(s):  
Seok Hoon Kang ◽  
Hyuk Moon
Keyword(s):  
Hard Of Hearing ◽  
Sound Pressure ◽  
Measured Data ◽  
Pressure Level ◽  
Experimental Equipment ◽  
Warning Message ◽  
The Hours ◽  
Set Up ◽  
And Control ◽  
Widespread Dissemination

Earphone use has skyrocketed due to the widespread dissemination of portable acoustic-apparatus. As the result, hearing loss due to noise-induced is becoming a big social problem. As the existing method, warning message is only used to prevent the hard of hearing according to the earphone use. However, it is hard for users to know the effect of the hours of earphone use and volume on their hearing, and control the earphone use by themselves. Therefore, in this paper, the method is suggested that users measure the effect of the time and volume of earphone use on their hearing with the simple experimental equipment and program. The method suggested in this paper is based on the simple experimental equipment to set up the similar environment to the real ear, and the program to find out the effect on hearing with the measured data.

Characterization and Design of a Non Ported Conventional Speaker for Acoustic Control

2005 ◽  
Author(s):  
Taehyun Shim
Keyword(s):  
Sound Pressure ◽  
Active Noise Control ◽  
Nonlinear Effects ◽  
Measured Data ◽  
Pressure Level ◽  
Design Procedures ◽  
Active Noise ◽  
Acoustic Control ◽  
Parameter Variations ◽  
Loud Speaker

A loud speaker has been widely used as a major actuator in the field of active noise control (ANC). In this paper, the design procedures for a non-ported conventional speaker that must meet restrictive size constraint as well as required sound pressure level at a targeted frequency for an acoustic control was presented. Dynamic model of a speaker that includes linear and nonlinear effects such as radiation resistance on speaker damping, voice coil electrical resistance has been developed and its responses were compared to measured data. The effects of speaker design parameter variations on a sound pressure and power consumption were also assessed experimentally and through simulation. It was found that the simulation results are well collated with experimental data and the desired objective has been met.

Prediction of Aeroacoustic and Control over a Cavity by Delayed Detached Eddy Simulation

2014 ◽  
Vol 598 ◽  
pp. 505-509 ◽  
Author(s):  
Yu Liu ◽  
Ming Bo Tong
Keyword(s):  
Sound Pressure ◽  
Noise Suppression ◽  
Cfd Simulation ◽  
Leading Edge ◽  
Pressure Level ◽  
Detached Eddy Simulation ◽  
Suppression Effect ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
And Control

In the present study CFD simulation with delayed detached eddy simulation (DDES) are performed to investigate an open cavity at Mach 0.85. Two cavity configurations, clean cavity and cavity with a leading-edge saw tooth spoiler, are modeled. The results obtained from clean cavity prediction are compared with experimental sound pressure level (SPL) data from QinetiQ, UK. Furthermore, comparisons are made with the predicted SPL between the two configurations. The main focuses of this investigation are to obtain a further understanding of the cavity aeroacoustics and test the noise suppression effect by a saw tooth spoiler.

Acoustics and Performance of High-Speed, Unequally Spaced Fan Rotors

1980 ◽  
Vol 102 (1) ◽  
pp. 19-27 ◽  
Author(s):  
S. Fujii
Keyword(s):  
Sound Pressure Level ◽  
High Speed ◽  
Sound Pressure ◽  
Pressure Ratio ◽  
Thermodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Measured Data ◽  
Pressure Level ◽  
Rotor Blades ◽  
High Pressure Ratio

This paper describes an experimental measurement of the effects of uneven blade spacing on the acoustic and aero-thermodynamic characteristics of high-speed, high-pressure-ratio fan rotors at two selected spacing configurations. A test rig, consisting of inlet guide vanes and transonic rotor blades, was employed to explore the redistribution of harmonic sound energy into a series of multiple tones of lower sound pressure level. The measured data indicated that a ten percent modulated rotor exhibited a six to eight decibel decrease in the sound pressure level as compared with the original first blade passage frequency harmonic. Disadvantages in aerodynamic performance resulting from spacing modulation were not so unfavorable for the ten percent modulated blades. However, with five percent modulated blades, serious deterioration in aerodynamic performance was observed particularly near the blade tip section, which produced an unfavourable acoustic signature. A calculation method, assuming a pulse event for each blade sound pressure, provided agreeable results with the measured data.

scholarly journals Experimental/Numerical Acoustic Assessment of Aircraft Seat Headrests Based on Electrospun Mats

2021 ◽  
Vol 11 (14) ◽  
pp. 6400
Author(s):  
Venanzio Giannella ◽  
Claudio Colangeli ◽  
Jacques Cuenca ◽  
Roberto Citarella ◽  
Mattia Barbarino
Keyword(s):  
Boundary Element Method ◽  
Experimental Validation ◽  
Sound Pressure ◽  
Pressure Level ◽  
Parallel Simulations ◽  
Aircraft Cabin ◽  
Acoustic Comfort ◽  
Set Up ◽  
Passenger Aircraft ◽  
Passive Noise

The work proposes a methodology for the assessment of the performances of Passive Noise Control (PNC) for passenger aircraft headrests with the aim of enhancing acoustic comfort. Two PNC improvements of headrests were designed to reduce the Sound Pressure Level (SPL) at the passengers’ ears in an aircraft cabin during flight; the first was based on the optimization of the headrest shape, whereas the second consisted of partially or fully covering the headrest surface with a new highly sound-absorbing nanofibrous textile. An experimental validation campaign was conducted in a semi-anechoic chamber. A dummy headrest was assembled in different configurations of shape and materials to assess the acoustic performances associated to each set up. In parallel, simulations based on the Boundary Element Method (BEM) were performed for each configuration and an acceptable correlation between experimental and numerical results was obtained. Based on these findings, general guidelines were proposed for the acoustical design of advanced headrests.

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.

Influence of the Acoustic Reflex on Vowel Recognition

1986 ◽  
Vol 29 (3) ◽  
pp. 420-424 ◽  
Author(s):  
Michael Dorman ◽  
Ingrid Cedar ◽  
Maureen Hannley ◽  
Marjorie Leek ◽  
Julie Mapes Lindholm
Keyword(s):  
Auditory System ◽  
Sound Pressure ◽  
Dynamic Range ◽  
Recognition Accuracy ◽  
Pressure Level ◽  
Acoustic Reflex ◽  
The Poor ◽  
Stapedial Reflex ◽  
Vowel Recognition ◽  
High Sound

Computer synthesized vowels of 50- and 300-ms duration were presented to normal-hearing listeners at a moderate and high sound pressure level (SPL). Presentation at the high SPL resulted in poor recognition accuracy for vowels of a duration (50 ms) shorter than the latency of the acoustic stapedial reflex. Presentation level had no effect on recognition accuracy for vowels of sufficient duration (300 ms) to elicit the reflex. The poor recognition accuracy for the brief, high intensity vowels was significantly improved when the reflex was preactivated. These results demonstrate the importance of the acoustic reflex in extending the dynamic range of the auditory system for speech recognition.

Pittenweem Priory and the conventuality question

2017 ◽  
Vol 68 (1) ◽  
pp. 19-37 ◽  
Author(s):  
Anthony Lodge
Keyword(s):  
Fifteenth Century ◽  
Traditional View ◽  
Archaeological Evidence ◽  
Significant Development ◽  
New Mother ◽  
Set Up ◽  
And Control

Pittenweem Priory began life as the caput manor of a daughter-house established on May Island by Cluniac monks from Reading (c. 1140). After its sale to St Andrews (c. 1280), the priory transferred ashore. While retaining its traditional name, the ‘Priory of May (alias Pittenweem)’ was subsumed within the Augustinian priory of St Andrews. Its prior was elected from among the canons of the new mother house, but it was many decades before a resident community of canons was set up in Pittenweem. The traditional view, based principally on the ‘non-conventual’ status of the priory reiterated in fifteenth-century documents, is that there was ‘no resident community’ before the priorship of Andrew Forman (1495–1515). Archaeological evidence in Pittenweem, however, indicates that James Kennedy had embarked on significant development of the priory fifty years earlier. This suggests that, when the term ‘non-conventual’ is used in documents emanating from Kennedy's successors (Graham and Scheves), we should interpret it more as an assertion of superiority and control than as a description of realities in the priory.

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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