Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 74 for “"Sound Pressure Level"”.
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Support vs. Steady Airflow: The Effect of Two Different Instructions on Subglottal Pressure, Sound Pressure Level, and Airflow Rate during Singing and Speaking
… that the word promotes the use of increased air pressure. The purpose of the present investigation was to test that hypothesis by examining differences in a variety of physiological parameters, comparing a conventional singing instruction that uses the word “support” with an alternative …
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A turbulent combustion noise model
… in this thesis. The model predicts (1) the pressure time series, (2) Sound Pressure Level (SPL) spectrum, (3) Over-All Sound Pressure Level (OASPL), (4) the thermoacoustic efficiency, (5) the peak frequency, and (6) the sound power of combustion generated noise. In addition, a correlation …
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Anomaly detection for environmental noise monitoring
Octave-band sound pressure level is the preferred measure for continuous environmental noise monitoring over raw audio because accepted standards and devices exist, these data do not compromise voice privacy, and thus an octave-band sound meter can legally collect data in public. By setting up an …
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Aerodynamic and Acoustic Modeling for eVTOL Rotor Noise Prediction
… variations in tonal blade-passing-frequency levels at 4000 revolutions per minute (RPM) and broadband spectral differences of approximately 4 dB. Despite these spectral variations, integrated overall sound pressure level predictions show limited sensitivity to turbulence model choice. At 2000 …
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Comfort studies on aircraft interior sound and vibration
… (BE97-4056) addressed the effects of combined sound and vibration (vibro-acoustics) on comfort sensation in aircraft. In the first study, seven cruising situations were presented in an aircraft mock-up and rated by 117 subjects using 15 polarities of a semantic differential. Principal component …
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Changes of voice production in artificial acoustic environments
The physical production of speech level dynamic range is directly affected by the physiological features of the speaker such as vocal tract size and lung capacity. However, the regulation of these production systems is affected by the perception of the communication environment and auditory …
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A Unified Measure of Audio System Fidelity
… of distortion as a function of the perceived Sound Pressure Level (SPL).
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Noise Levels in a South African bank cash centre
… within the cash centres are exposed to noise levels that could be damaging to the auditory system and warrants the implementation of a hearing conservation programme. In order to investigate the noise levels emitted during cash management processes, the researcher obtained noise level …
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Characterizing The Acoustic Properties Of The Jet Lab At The National Center For Physical Acoustics
… were acquired at each frequency to calculate the sound pressure level and determine if the calculated values are within the allotolerance of the inverse square law.
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The Effects of Divided Attention on Speech Motor, Verbal Fluency and Manual Motor Task Performance
… displacement and peak velocity decreased, while sound pressure level and spatiotemporal variability increased. The impact of manual motor performance on speech differed between the right and left hand. Manual motor scores significantly decreased when concurrently performed with the verbal fluency …
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Computer assisted audiometric evaluation system
… microphone eliminates the need for a sound pressure level meter during speech tests. The software-based user-interface makes use.of overlaid pop-up menus, context sensitive assistance.and a text editor on a graphics screen. Pure tone and speech data are acquired and displayed on a …
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Experimental measurement of combustion noise and comparison to a predictive model
… The data are presented in the form of acoustic pressure spectra and over-all sound pressure levels. The experiment consisted of a geometrically simple pre-mixed burner with five interchangeable nozzles whose diameters varied from 0.117 cm to 0.541 cm. The fuels examined in the experiment were …
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Experimental investigation of the flow field during combustion in narrow circular ducts
… wave propagation analysis also yielded a sound pressure level consistent with audio perception during flame oscillations with acoustic emissions.
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Toward a micro-scale acoustic direction-finding sensor with integrated electronic readout
… sensor can be exposed to at least 162 decibel sound pressure level with no loss of function. Next, an improved capacitive readout system using branched comb fingers is presented. This design is shown to double electrical sensitivity to motion. Finally, it is shown that residual stress-induced …
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Implementation of Refractory Foam Technology for Silencing Small IC Engines
… areas of noise reduction, weight, size, and backpressure, compared to commercial designs. The final silencer design boasted an Aweighted overall sound pressure level that was 12.1 dBA lower than the reference case. This result was accomplished using nearly half the volume required by other …
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Numerical Analysis of Gun Barrel Pressure Blast Using Dynamic Mesh Adaption
… (CFD) method has been applied to simulate the pressure blast of the projectile which is launched from a barrel and to investigate the pressure distribution and sound pressure level (dB) along different positions away from the gun axis and towards the fuselage of the aircraft. Fluent was …
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Repurposing Oseltamivir, a Commonly Prescribed Influenza Antiviral, for the Prevention of Noise- and Cisplatin-Induced Hearing Loss
… permanent hearing protection of 15-25 decibel Sound-Pressure Level (dB SPL) for both female and male mice. In mice, oseltamivir treatment reduced outer hair cell death after cisplatin treatment and mitigated cochlear synaptopathy after noise exposure. We showed that a potential binding protein, …
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How individuals with Parkinson's disease modify their speech in a repetition for clarification
… in a repetition. Fundamental frequency (F0) and sound pressure level (SPL) were not consistently modified in repetitions for clarification. Under most speaking conditions, individuals with PD and controls had similar F0 and SPL. Individuals with PD, like the controls, responded to the …
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Tone-evoked Fos labeling in the central auditory pathway : effects of stimulus intensity and auditory fear conditioning
… of the brain in awake animals. Increasing sound pressure level led to: (1) spreading of labeling towards neurons with higher best frequencies; (2) spread of labeling orthogonal to the tonotopic axis; (3) and increased density of labeling within the tonotopic band. In addition to encoding …
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Determination of acoustic ray paths in enclosed spaces
… ray paths were used along with the power level of the source and the absorptive characteristics of all the reflecting surfaces to determine the sound pressure levels at specified receiver locations. A computer program was developed to perform the necessary calculations for reflection …
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