In an early experiment using synthetic speech, it was shown that raising or lowering the formants in an introductory sentence affected the identification of the vowel in a following test word [P. Ladefoged and D. Broadbent, J. Acoust. Soc. Am. 29, 98-104 (1957)]. This experiment has now been replicated using natural speech produced by a phonetician using two different overall settings of the vocal tract.