Aircraft noise

About: Aircraft noise is a research topic. Over the lifetime, 3051 publications have been published within this topic receiving 32039 citations.

Three-Way Spectral Decompositions of High-Performance Military Aircraft Noise

Abstract: High-performance military aircraft noise contains large- and fine-scale turbulent mixing noise and broadband shock-associated noise. A three-way spectral decomposition quantifies the contribution f...

Aeroengine noise investigated from flight tests

Abstract: Over one hundred acoustic flyover tests were performed with an Airbus A319 in 2004 with the objective to improve some existing aircraft noise prediction tools developed by DLR to investigate noise abatement procedures. The present paper deals with the noise emission of the two CFM56-5A5 engines and some installation effects. The analysis is based on acoustic dedopplerized spectra and localization maps calculated with the pressure signals of a phased array of 168 microphones. This study shows that the prediction of jet mixing noise collapses reasonably well with the measurements, a modal analysis of buzzsaw tones based on the farfield directivity gives results in agreement with the theory of buzz-saw tone generation, the amplitude of the blade passing frequency tone depends on the slat/flap settings and airspeed but not on the landing gear position. As outlook some preliminary results calculated with a source amplitude assessment method are presented.

Mitigating the Effects of Military Aircraft Overflights on Recreational Users of Parks

Abstract: : This study was initiated as part of the cooperative US Air Force/National Park Service efforts to understand and effectively manage the potential adverse effects military air crew training can have on the National Parks. Through simultaneous sound data acquisition and Park user interviews, data were collected that provided a basis for determining how military jet overflights can affect visitor experience at a site in White Sands National Monument, New Mexico. Several useful findings resulted from the analysis. First, visitors can distinguish between the concepts of "annoyance" and "interference" produced by aircraft sound. Annoyance is an emotional reaction, while interference is more of an objective judgment. Visitors can find that the sound of aircraft interferes with the natural soundscape, but are not necessarily annoyed. Visitors believe annoyance results if the interference is often or severe enough. Second, visitors tend to be less annoyed by aircraft noise if they remember learning that they could hear or see aircraft while in the Park. This finding shows the importance of informing visitors about possible aircraft overflights - i.e., managing visitor expectations. Finally, aircraft noise is likely to produce less annoyance if aircraft fly over in close succession, rather than widely spaced, one at a time.

A new field-laboratory methodology for assessing human response to noise

Abstract: Gross measures of community annoyance with intrusive noises have been made in a number of real environment surveys which indicate that aircraft noise may have to be reduced 30-40 EPNdb before it will generally be considered acceptable. Interview studies, however, cannot provide the precise information which is needed by noise abatement engineers of the variable human response to different types and degrees of noise exposure. A new methodological field-survey approach has been developed to provide such information. The integrated attitudes and experiences of a random sample of subjects in the real environment are obtained by a prior field survey. Then these subjects record their more precise responses to controlled noise exposures in a new realistic laboratory. The laboratory is a sound chamber furnished as a typical living room (18 ft x 14 ft) and subjects watch a color TV program while they judge simulated aircraft flyovers that occur at controlled levels and intervals. Methodological experiments indicate that subjects in the laboratory have the sensation that the airplanes are actually moving overhead across the ceiling of the chamber. It was also determined that annoyance judgments in the laboratory stabilize after three flyovers are heard prior to a judgment of annoyance.