On the applicability of Kramers-Kronig relations for ultrasonic attenuation obeying a frequency power law

In the recent literature concern has been raised regarding the validity of Kramers-Kronig relations for media with ultrasonic attenuation obeying a fr equency power law. It is demonstrated, however, that the Kramers-Kronig dis persion relations for application to these types of media are available. Th e developed dispersion relations are compared with measurements on several liquids, and agreement is found to better than 1 m/s over the experimentall y available bandwidth, A discussion regarding the validity of these dispers ion relations, in particular how the dispersion relations relate to the so- called Paley-Wiener conditions, forms the conclusion. (C) 2000 Acoustical S ociety of America. [S0001-4966(00)03107-6].