Experimenters have frequently noted large individual differences in listeners' abilities to discriminate auditory patterns differing only in the frequency of one pattern component. Whereas some subjects require weeks of practice with large pattern differences, others can make fine discriminations almost immediately. To further characterize such subject‐dependent differences in performance, we investigated pattern discrimination by listeners with only minimal paychoacoustic experience. Since most naive listeners can detect a frequency change if the target component is much longer than the other pattern components, we measured the target tone duration required for correct discrimination 71% of the time in a standard/2AFC procedure, for five levels of target frequency difference (Δ ∫) ranging from 18 to 92 Hz. Nine of the ten pattern components were 45 ms in duration, while the target tone duration varied according to an adaptive track. The target tone (920 Hz) was always the second pattern component. The nine other tones, with frequencies between 500 and 1500 Hz, were randomly ordered on every trial. Threshold durations were estimated from adaptive tracks for each Δ ∫. Generally longer target tone durations were required to discriminate small Δ ∫'s than for larger frequency differences, paralleling the effects of duration on frequency discrimination of brief tones in isolation. Each listener clearly fell into one of two nonoverlapping groups: those with high duration thresholds for all Δ ∫'s tested, and those who consistently required much shorter target tone durations.