Time-frequency analysis provides a detailed means to characterize features of sounds which might affect animals. Graphic displays of the analyzed sound fields often reveal qualitative patterns and quantitative measures that can be used as a basis for comparing different sound fields. The displays can be animated and presented in conjunction with audio recordings of the sounds and with video recordings of the environments in which the sounds were produced in order to assist in identifying sources and effects of the sounds. Modular signal processing software, integrated with a high level programming language and operated on graphics workstations enable the researcher to select specific types of sounds which are found to occur in typical environments of selected animals. The system can also be used to synthesize calibrated sets of similar sounds to be used as inputs for controlled experiments investigating the effects of the sounds on animals. In this paper, a typical workstation-based system for performing time-frequency analysis of digitally recorded sound will be described. Operation of the system will be illustrated with results from analyses of sounds collected during a recent survey of the acoustic environments of captive and wild fish and with specialty sounds synthesized for current investigations of effects of noise on fish.