Recordings were made of seismic pulses by explosive sources in rock underground at Mount Isa Mine, Queensland, Australia. Analysis of the experimental results in light of the theory of Kjartansson (1979) indicates that the simple rise time law &tgr;=&tgr;0+CT/Q is inadequate for describing the attenuation of seismic pulses generated by a realistic source. The rise time law makes no allowance for the spectral characteristics of the source except by assigning a value of &tgr;0 to each source and is an oversimplification of the process of source propagation through rocks; consequently, the constant C is source dependent. An alternative method of estimating pulse attenuation is presented, which overcomes the difficulties inherent in the rise time law.