Woodruff School of Mechanical Engineering

Guest Speaker


Predicting the Impact of Aircraft Noise


Dr. Patricia Davies


Purdue University


Monday, April 9, 2012 at 11:00:00 AM


MRDC Building, Room 4211


Dr. Erica Ryherd


Annoyance and sleep disturbance are two impacts of aircraft noise on communities around airports. Currently, Day Night Level (DNL), a metric based on the average A-weighted sound pressure level outdoors is used to assess the impact of the noise. There are arguments made that we should look for a better annoyance metric than DNL. Some are based on an increased understanding of how sound is perceived and the importance of sound characteristics, in addition to loudness, that can affect annoyance. As an illustration, some experiments designed to examine how the presence of tonal components affects aircraft noise ratings are described. Others argue that the number of aircraft noise events influences annoyance as well as the level of the events, and that the average energy approach of most environmental noise metrics does not capture this. There is a 10 dB penalty for noise events at night incorporated into DNL, but sleep disturbance is a function of individual event characteristics and this penalty does not properly account for increased awakening due to aircraft noise nor is it related to the effect that noise exposure may have on sleep structure. However, before any new noise metric is adopted, it must be shown to be a more accurate predictor of community impact than DNL, and that there are sound prediction tools available to provide the necessary input to the metric calculation. The talk is focused on what needs to be done to effect such a change.


Dr. Patricia Davies received her B.Sc. in Mathematics from the University of Bristol, and her M.Sc. and Ph.D. in Sound and Vibration from the University of Southampton, both in the UK. She is currently a Professor of Mechanical Engineering at Purdue and teaches courses in measurements, controls, signal processing and mechanics. Dr. Davies is the Director of the Ray W. Herrick Laboratories, where she also conducts research in the areas of sound perception, signal processing, and nonlinear system identification. Her research has been funded by government and by industry. She has applied her research to modeling of human response to machinery and transportation noise; modeling the dynamics of viscoelastic materials and seat-occupant systems; visualization of automobile noise sources during pass-by tests; predicting machinery failure; and development of automatic analysis tools for classification of infant and mother laughter. She co-founded a Perception-based Engineering Center at Purdue, a collaborative research group of engineering and psychology professors. Dr. Davies is a Fellow of the Institute of Noise Control Engineering and served as its President from 2008 to 2010.


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