A different way of showing there are,indeed, two dominant noise components is to look at the directivities of noise
contours at a fixed frequency. Fig. 31 is a plot of the directivities from 300 Hz to 4000 Hz. The direction of maximum noise
radiation is a round 1151. Fig. 32 is a similar directivity plot for frequencies of 50, 70 and 100 Hz .For these low frequencies,
the direction of maximum noise radiation is around 1401. Fig. 33 is a combined plot of Figs. 31 and 32. It shows that for the
F-22A aircraft,there are two distinct jet noise radiation patterns . This indicates that there are two distinctly different sources
of noise(note:the 200 Hz contour exhibits two separate peak directions of radiation).The low - frequency component is the
large turbulence structures noise. The high - frequency component comes from the new noise source.