Eight normal-hearing individuals and six single-electrode cochlear implant users were asked to discriminate tape recorded pairs of spoken monosyllables consisting of 11 English syllabic nuclei (see formula in text) bounded by the consonant frame. A same-different paradigm was used. Most normal-hearing subjects discriminated all pairs intended by the talker as different; two normal listeners confused monosyllables containing (see formula in text). Cochlear implant users showed some intersubject variation, but for the 6 subjects, discriminations were consistent enough to allow the data to be pooled for analysis. The pooled data for these four subjects indicated that high front and high back vowels were discriminable from low vowels. The basis for the discriminations is difficult to evaluate, since the naturally spoken stimuli varied with respect to formant frequencies, fundamental frequency, intensity, and duration.