Jitter‐detection thresholds were determined over a wide range of pulse levels and in the presence of band‐limited masking noise. Pulse level modifies jitter thresholds of high pulse frequencies substantially more than that of low and intermediate pulse frequencies. This result is apparently at variance to that predicted by a simple temporal coding underlying auditory jitter. Noise masking is substantially more effective upon relatively low‐frequency pulse trains (average interpulse intervals between 2 and 15 msec) than upon higher‐frequency pulse trains. Noise masking by low or high noise frequencies is substantially less effective than intermediate noise frequencies, in the vicinity of 1 kHz. This frequency region has also been implicated by other investigators as critical for pulse‐frequency discrimination.