CRITICAL SOUND DAMPING - WHEN DOES SCALING HOLD

Using the dynamic specific-heat theory, we show that exponent y, assoc iated with high-frequency damping at a second order phase transition ( delta<(alpha)over bar> similar to omega(1+y)), is frequency-dependent. This result indicates that the dynamic scaling-laws predicting that t he delta<(alpha)over bar>/delta<(alpha)over bar>(infinity) ratio is a homogeneous function of variable omega tau are never rigorously verifi ed (tau is the critical relaxation time). This calculation, which allo ws the degree of departure from these laws to be determined, is applie d to various experimental situations.