Budgerigars (parakeets) were trained using operant conditioning procedures to detect changes in a repeating background of synthetic speech sounds. Response latencies for detection were used to construct similarity matrices, and multidimensional scaling procedures were then used to produce spatial maps of these speech stimuli reflecting perceptual organization. Birds were tested on the same alveolar, velar, and bilabial synthetic VOT stimuli previously used to test humans and chinchillas [P. K. Kuhl and J. D. Miller, J. Acoust. Soc. Am. 63, 905–917 (1978)]. Results indicate that budgerigars partition each of these continua into two perceptual categories with an abrupt perceptual change occurring at roughly the same VOT location as observed in humans and chinchillas. It is concluded that the perceptual mechanisms underlying the categorigal perception of VOT stimuli are sufficiently general so as to be common to the mammalian and avian auditory systems. [Work supported by NIH.]