No abstract

The attenuation of acoustic waves is often in the form exp½Àaj!j b with 05b 2. For b ¼ 2, experiments show negligible dispersion. For b ¼ 1, the variation of the velocity is well-fitted by a logarithmic function, and by power functions when b 6 ¼ 1. An explanation of theses results has been provided by T.L. Szabo by extensions of the Kramers-Kronig relations. In this paper, we show that a random propagation time leads to similar results. This model explains the loss of power by the existence of noise which cannot be taken into account by the devices. Also, it explains the redshift linked to the wave bandwidth.

No abstract

No abstract

No abstract