Intelligibility, redundancy (frequency domain), and phoneme confusions of speech were investigated through narrow‐band filtering. Filtered syllables (CV) and words (CVC) were presented to twelve paid, normally hearing subjects. Stimuli consisted of 17 English consonants paired with three vowels /i, u, a/, and filtered through five conventional one‐third octave bands centered at 0.5, 1, 2, 3.15, and 4 kHz, and one ’’critical’’ band (500 Hz wide) centered at 3.15 kHz. Results revealed (1) no significant differences between syllable and word intelligibility; (2) word or syllable intelligibility was maximum (50%) for the band centered at 2 kHz, and was greater for the bands above 2 kHz compared to those situated below this frequency; (3) speech intelligibility was reduced for the critical band compared to the one‐third octave band centered at 3.15 kHz; (4) about half of the syllables or words were perceived correctly in more than one band reflecting redundant perceptual cues along the frequency domain; and (5) consonantal‐confusion data revealed thatmannerandvoicingfeatures were least affected, and theplacefeature was most affected by filtering.