Illustrations are given of information carried in the waveforms and frequency spectra of acoustic emissions. The effects of multiple reflections and resonances are discussed. A model of the acoustic‐emission source wave is developed, and arguments are given why this wave should be a pulselike function, rather than an oscillatory function of stress. Further use of this model may allow more quantitative treatment of emission amplitudes, energies, and spectra. Experimental results show the use of two instruments for the evaluation of emission spectra. The feasibility of using frequency analysis to obtain information about source events is demonstrated.