Refinements in the Resonator Sound Speed Technique and Sound Exposure in Motorsports Audiences

date October 18, 2013
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Friday, October 18, 2013 4:00 p.m. in ETC 4.150

Craig NDolder
Applied Research Laboratories and Department of Mechanical Engineering
The University of Texas at Austin

This seminar covers two independent topics.  The resonator sound speed technique has been used by researchers at the University of Texas at Austin to determine the acoustic effective medium properties of freely rising bubbles in water, methane hydrates, seagrass, fluid-like gas-bearing sediment, and recently fish schools.  Despite the robust nature of this method for non-dispersive materials, the interpretation of the acoustic field present in the resonators is not intuitive for dispersive media.  However, when measured acoustic resonance frequencies can be correctly associated with the appropriate acoustic mode, interesting insight into highly dispersive systems can be gained.  This presentation walks through recent improvements and insights regarding this technique.  The second topic covers the initial analysis of calibrated sound recordings taken at a recent motorsports event.  These recordings were analyzed in order to provide the noise dosage seen in three different spectator locations.  The results show that spectators are exposed to more noise than is allowed by the OSHA standards for workplace safety.