Explanations of phonetic perception describe the conversion of the acoustic signal to phonetic segments. By making the descriptions of phonetically relevant patterns abstract, these explanations have accomodated the great variability evident in the acoustic signals produced by different talkers and in different utterances by the same talker. In order to refine this characterization of perception, we sought to determine the precise limits of phonetically useful information over frequency variation. A frequency transposition test was performed with three sentences, employing the technique of sinusoidal replication of natural utterances. This technique emphasized time‐varying acoustic information, and also controlled for timbre changes over frequency. The results show that a phonetic listening band may exist within the human range of audible frequencies. The relation of this finding to frequency coding, perception of musical pitch, and development of sensory prostheses will be discussed. [Supported by the National Institute of Child Health and Human Development.]