The pattern of phoneme recognition and phoneme confusions shown by fluent and nonfluent aphasic and nonaphasic subjects with regard to place of articulation and voicing was examined in a listening task using synthesized speech stimuli. Subjects were asked to recognize six stop consonant vowel syllables (/pa,ba,ta,da,ka,ga/) under three formant frequency conditions (synthesized presentation of F[inf 1], F[inf 2], and F[inf 3]; attenuation of F[inf 2]; and attenuation of F[inf 3]). A series of confusion matrices was developed to document the voicing and place of articulation responses made by each group across all formant conditions. Analysis of phoneme recognition and phoneme confusions revealed that nonaphasic errors centered on substitutions along the place of articulation continuum. Both fluent and nonfluent aphasic groups demonstrated this place of articulation substitution pattern, but with more numerous errors, additional substitutions of voice, and combinations of voicing and place of articulation errors, particularly in the nonfluent aphasic group. Implications of the results are discussed.