Statistical Phenomena

Statistical analysis is applied to phenomena associated with propagation of random nonlinear acoustic waveforms in homogeneous media. Following presentation of the nonlinear evolution equation and relevant statistical functions, basic phenomena in nonlinear noise fields are described for an initially quasi-harmonic signal with random amplitude and phase modulation. An expression is presented for the intensity of the harmonics generated by a source radiating narrowband noise. Examples are provided illustrating the widening of the frequency spectrum associated with propagation of broadband noise of finite amplitude, and with interaction of a finite-amplitude tone with a band of low-amplitude noise.