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Showing papers on "Noise pollution published in 1968"



Journal Article
TL;DR: Objectionable community noise sources include automobiles, trucks, buses, motorcycles, trains, and power driven equipment such as lawn mowers.
Abstract: Objectionable community noise sources include automobiles, trucks, buses, motorcycles, trains, and power driven equipment such as lawn mowers. Noise control procedures can be applied to the source, the transmission path, residential zoning, or through legislation.

5 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider the powerplant noise in terms of disk loading, progressing from jets at the high end down through fans, propellers, and rotors, leading to selection of rotors and propellers for shorthaul propulsion.
Abstract: An increase of background noise has accompanied the steady growth of industrial society. Rapid growth of air travel has focused special attention on aircraft noise, and need for abatement. Anticipated growth of short-haul air transport will bring vertiports into established commercial areas and low-altitude flyovers to populated areas. Noise intrusion may be assessed in perceived noise (PNdb) for residential communities, but a more realistic yardstick for commercial/industrial sections might be speech interference level (SIL). Achievement of the ideal goal—no intrusion of noise above ambient levels—requires reduction of powerplant noise but may be limited by aerodynamic noise from the vehicle itself. Consideration of powerplant noise in terms of "disk loading," progressing from jets at the high end down through fans, propellers, and rotors, leads to selection of rotors and propellers for shorthaul propulsion. Further noise reduction below current state-of-the-art levels will require intensive long-range development programs. Parallel to concentrated effort by industry to provide aircraft acoustically acceptable to the community, the community should plan for these aircraft by judicious selection of vertiport sites and utilization of zoning and building-code functions for development of surrounding neighborhoods.

4 citations