Constant frequency (CF) and frequency‐modulated (FM) pulses were utilized to examine the response characteristics of collicular neurons. Tonic, toniclike and various types of phasic “on” responses were noted depending upon the type of stimulus used. For example, a tonic response patten elicited from a given neuron with CF stimulation could be changed to a phasic “on” pattern with FM stimulation. Similarly, thresholds and input—output functions were affected by the stimulus type. Superimposed upon the effects of stimulus type were the effects of stimulus duration. Many neurons were found to have firing patterns and response characteristics to long duration stimuli that differed greatly from those observed with shorter signals having durations less than 2.0 msec. Results suggest that most inferior collicular neurons are best suited for extracting information from signals having durations comparable to those emitted during the search and approach phases of goal‐directed flight and are poorly suited for responding to shorter signals having durations typical of those emitted during the terminal phase of echolocation. [Supported by NSF Grant P401855‐000.]