TY - GEN
T1 - On the perception of crackle in noise radiated from military jet aircraft
AU - Gee, Kent L.
AU - Sparrow, Victor W.
AU - Atchley, Anthony
AU - Gabrielson, Thomas B.
PY - 2006
Y1 - 2006
N2 - Crackle is a phenomenon sometimes found in supersonic jet noise. It has been commonly quantified by the skewness of the time waveform. In this investigation, a simulated waveform with a virtually identical probability density function and power spectrum as an actual F/A-18E afterburner recording has been created by nonlinearly transforming a statistically Gaussian waveform. Although the afterburner waveform crackles noticeably, playback of the non-Gaussian simulated waveform yields no perception of crackle at all, despite its relatively high skewness. Closer examination of the two waveforms reveals that although they have virtually identical statistics, there are considerable differences in their time rates of change in the intense compressive portions of the waveforms. The afterburner waveform is much more shock-like with its more rapid variations in pressure that the non-Gaussian simulated waveform. This results in a significant difference in the probability distributions of the time derivatives of the actual and simulated data and suggests that the perception of crackle in jet noise waveforms may be better quantified with statistics of the time derivative of the waveform, rather than by the skewness of the time waveform itself.
AB - Crackle is a phenomenon sometimes found in supersonic jet noise. It has been commonly quantified by the skewness of the time waveform. In this investigation, a simulated waveform with a virtually identical probability density function and power spectrum as an actual F/A-18E afterburner recording has been created by nonlinearly transforming a statistically Gaussian waveform. Although the afterburner waveform crackles noticeably, playback of the non-Gaussian simulated waveform yields no perception of crackle at all, despite its relatively high skewness. Closer examination of the two waveforms reveals that although they have virtually identical statistics, there are considerable differences in their time rates of change in the intense compressive portions of the waveforms. The afterburner waveform is much more shock-like with its more rapid variations in pressure that the non-Gaussian simulated waveform. This results in a significant difference in the probability distributions of the time derivatives of the actual and simulated data and suggests that the perception of crackle in jet noise waveforms may be better quantified with statistics of the time derivative of the waveform, rather than by the skewness of the time waveform itself.
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M3 - Conference contribution
AN - SCOPUS:33845668347
SN - 1563478099
SN - 9781563478093
T3 - Collection of Technical Papers - 12th AIAA/CEAS Aeroacoustics Conference
SP - 1681
EP - 1689
BT - Collection of Technical Papers - 12th AIAA/CEAS Aeroacoustics Conference
T2 - 12th AIAA/CEAS Aeroacoustics Conference
Y2 - 8 May 2006 through 10 May 2006
ER -