Sound-pressure levels were measured on the ground while the helicopter flew over an array of microphones placed either in an open field or in the centre of a city street confined by tall buildings. It was found that the noise in the latter case was initially lower but built up to a higher peak, an effect attributed to a reverberant sound field in the street. A quantitative theoretical explanation is given.
Helicopter noise experiments in an urban environment
Hubschraubergeraeuschmessungen in staedtischer Umgebung
Journal of the Acoustical Society of America ; 56 , 2 ; 332-337
1974
, 8 Quellen
Article (Journal)
English
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