Listeners tend to experience rising pitch even though frequency falls as a sound source approaches. The phenomenon, called the Doppler illusion [J. G. Neuhoff and M. K. McBeath, J. Exp. Psychol. Hum. Percept. Perform. 22, 970--985 (1996)], shows that dynamic intensity change influences perceived pitch in a way that is qualitatively different from discrete static intensity change. Two new studies show a dynamic influence of intensity change on perceived pitch and a dynamic influence of frequency change on perceived loudness. Listeners were presented with square wave tones of either rising, falling, or constant intensity that either rose, fell, or remained constant in frequency for 6 s. Listeners responded in real time to either changes in pitch or loudness by moving a response wheel. It was found that dynamic intensity sweeps contribute to the perception of dynamic pitch change in the direction of the intensity sweep. In addition, dynamic frequency sweeps contribute to the perception of perceived loudness change in the direction of the frequency sweep. The results imply that pitch and loudness perception interact under dynamic conditions in a way that cannot be predicted by perceptual models derived from the presentation of discrete static tones.