Analysis and correction of ground reflection effects in measured narrowband sound spectra using cepstral techniquesGround reflections generate undesirable effects on acoustic measurements such as those conducted outdoors for jet noise research, aircraft certification, and motor vehicle regulation. This paper shows how cepstral techniques developed in speech processing can be adapted to identify the echo delay time and to correct for ground reflection effects. A sample result is presented using an actual narrowband sound pressure level spectrum. The technique can readily be adapted to existing fast Fourier transform type spectrum measurement instrumentation to provide field measurement of echo time delays.
Document ID
19760042173
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Miles, J. H. (NASA Lewis Research Center Cleveland, OH, United States)
Stevens, G. H. (NASA Lewis Research Center Cleveland, Ohio, United States)
Leininger, G. G. (Toledo, University Toledo, Ohio, United States)