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.
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Showing 1 to 14 of 14 for “"earplug"”.
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Effects of Earplug Material, Insertion Depth, and Measurement Technique on Hearing Occlusion Effect
… Also, an experiment to determine the effect of earplug types (differing in material and design), insertion depth, and excitation sources was conducted. Lastly, the noise attenuation capability of medical balloon-based earplugs was tested. Ten subjects, six male and four female, volunteered for …
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Approaches to understanding the cumulative effects of stressors on marine mammals.
… mammals and suggested the use of baleen whale earplugs to evaluate both stress and stressors. The objective of this dissertation is to investigate historic and current organic and inorganic contaminants within the marine ecosystem to better understand the cumulative effects of stressors on …
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Field evaluation of noise attenuation and comfort performance of earplug, earmuff, and ear canal cap hearing protectors under the ANSI S12.6- 1984 sound field standard
… comfort achieved with a user-molded foam earplug, a premolded, triple-flanged polymer earplug, a popular foam cushion earmuff, and an ear canal cap with compliant rubber earpods. Workers were pulled from their workplaces without prior knowledge of when they were to be tested and without …
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Finite Element Modeling and Exploration of Double Hearing Protection Systems
… covered to simulate human flesh, and a foam earplug installed inside a rigid cylinder designed to simulate the human ear canal. Pressure readings are taken at the bottom of the simulated ear canal assembly. Advanced finite element models are used to reconcile differences between the …
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The Detection of Warning Signals While Wearing Active Noise Reduction and Passive Hearing Protection Devices
… a passive earmuff, and a user-molded foam earplug were tested in two types of noises (pink and red) at two different noise levels (85 dBA and 100 dBA). The signal used was an industry-standard backup alarm. The experimental design was completely within-subjects. An ascending method of …
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Azimuthal Localization and Detection of Vehicular Backup Alarms Under Electronic and Non-Electronic Hearing Protection Devices in Noisy and Quiet Environments
… conditions tested. However, the E-A-R/3M HiFiTM earplug was advantageous in localization performance since it provided a significantly higher percentage correct localization than the Moldex foam earplug, the diotic earmuff, and the dichotic earmuff in 90 dBA pink noise. As for main effects of the …
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An inter-laboratory investigation of ANSI standard fitting protocols, sample size, subject and experimenter gender, and trial on the real-ear attenuation of two types of earplugs
… at threshold (REAT) of a popular vinyl foam earplug and a multi-sized premolded PVC single-flanged earplug. The first fitting procedure tested in the experiment is included in the revision of the American National Standards Institute (ANSI) standard S12.6-1984 by the ANSI Working Group ANSI …
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An In-Field Experiment on the Effects of Hearing Protection/Enhancement Devices and Military Vehicle Noise on Auditory Localization of a Gunshot in Azimuth
… one passive (3M's Single-Ended Combat Arms earplug) and three electronic level-dependent HPEDs (Peltor's Com-Tac II electronic earmuffs and Etymotic's EB 1 and EB 15 High-Fidelity Electronic BlastPLG earplugs), in comparison to the open ear in an in-field test environment with ambient …
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Measurement of head acceleration and angular rate experienced by aerobatic pilots
… with tri-axial accelerometer and angular rate earplug sensors. A second tri-axial accelerometer and angular rate sensor package was fixed to the plane. For each subject, data were collected from the two synchronized sets of hardware during a 10-minute practice session. The recordings of the …
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Patient Satisfaction Related to Noise in the Coronary Care Unit
… promotion. From September to November 2014, earplugs were offered to all alert/oriented patients entering the CCU. Data were analyzed using the tracking tool for earplugs and the CCU Press Ganey scores for noises in and around the patient room.</p> <p><strong>Results </strong> A direct result …
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The effects of hearing protection on speech discrimination in differing noise spectra
… subject's hearing configuration (unoccluded or earplug, earcap, earmuff-occluded), 2). ambient noise intensity level (60, 83 dBA), 3). ambient noise spectral type (low, white approximation, high frequency), 4). speaker's voice level (63 or 65 dBA in 60 dBA noise, 82 or 88 dBA in 83 dBA noise), …
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Psychophysical investigation of the real-ear attenuation of hearing protection devices under different sound-field diffusivity conditions
… hearing protectors (three earmuffs and one earplug) at each of nine 1/3 octave band frequencies centered at 125, 250, 500, 1000, 2000, 3150, 4000, 6300, and 8000 Hz. One testing environment comprised a reverberant room with three loudspeakers, one firing in each room plane, that met all the …
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Laboratory investigation of in-field influences on spectral noise attenuation and comfort of insert and circumaural hearing protectors
… a popular foam cushion earmuff, two types of earplugs (user-molded foam and pre-molded, triple-flanged polymer), and an earmuff over foam earplug combination. Both attenuation and comfort data were collected from 40 naive but audiometrically normal subjects. Using a psychophysical …
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An Examination of Headset, Hearing Sensitivity, Flight Workload, and Communication Signal Quality on Black Hawk Helicopter Simulator Pilot Performance
… also showed that a passive headset/passive earplug combination use by the hearing-impaired group of pilots led to degradation of certain flight performance parameters and lower ratings of SA than the headsets equipped with assistive communication technology; however, the same headset effect …