The consonant environments of vowels were varied by forming nonmeaningful stimulus syllables consisting of 72 combinations of six vowels and 12 consonants. The syllables were spoken by subjects, and the duration, fundamental frequency, and relative power of the vowels were measured. All three factors varied significantly in response to changes of the consonant environment. The variations were systematically related to the attributes of the consonants, the most powerful attribute being the presence or absence of vocal fold vibration, followed by manner of articulation and place of articulation, in that order.