A number of recent studies attribute selective adaptation effects in whole or in part to response contrast rather than to desensitization of “feature detectors” [J. S. Bryant, J. Exp. Psychol. 4, 610–620 (1978); R. L. Diehl, J. L. Elman, and S. B. McCusker, J. Exp. Psychol.4, 599–609 (1978); H. J. Simon and M. Studdert‐Kennedy, J. Acoust. Soc. Am.64, 1338–1357 (1978)]. The hypothesized detectors were generally assumed to be available only for certain consonantal features; such phenomena as the susceptibility of vowel identity judgements to contextual effects were thus considered to be unrelated. Selective adaptation experiments were performed using acoustic continua spanning the ranges from steady‐state [ε]to [εl] and from [εl]to [εd]. Endpoint adaptors in both experiments produced significant shifts in the predicted directions. The results fit well with a response‐contrast interpretation, and argue against a strict perceptual dichotomy based on consonant/vowel classification alone.