ABSTRACTEach of 40 college students received 6 presentations of white noise at an intensity of either SO or 110 dB during either inspiration or expiration. Changes in tidal volume, inspiratory period, and expiratory period elicited by that stimulation were studied. Auditory stimulation produced respiratory changes which could be regarded conveniently as two phasic responses. We labeled these responses the initial phasic response and the delayed phasic response. The initial response was limited to the respiratory period during which stimulation was delivered, it consisted of a brief inspiratory movement which increased the speed of inspiratory periods during which it occurred but decreased the speed of expiratory periods during which it occurred. In either case, the initial phasic response increased ventilation. The delayed phasic response was an increase both in speed and tidal volume of respiratory cycles subsequent to the period during which stimulation was delivered. Like the initial response, the delayed response increased ventilation. The effects of the delayed response were more widespread when stimulation was delivered during expiration rather than during inspiration. Stimulus intensity and stimulus repetition respectively potentiated and attenuated both the initial and the delayed phasic response. The findings are compared with those of earlier research on respiratory changes elicited by auditory stimulation.