We studied American English speech rhythm using reiterant speech with the prosody of normal speech but without its segmental variations. Syllable duration was strongly influenced by stress and by final positions in words and phrases, but negligibly by nonfinal positions within words and phrases. Word duration increased linearly with word size, and varied with stress pattern for words of constant size. Metrical foot duration increased approximately linearly with foot size. Feet of the same type and size were of constant duration.