We describe two experiments with 16 Nu cleus® CI users, where we controlled modulation characteristics and carrier rate using Spectral and Temporal Enhanced Processing (STEP), a novel experimental multichannel sound coder. We used a fixed set of threshold and comfortable stimulation levels for each subject, obtained from clinical MAPs. In the first experiment, we determined equivalence for voice pitch ranking and voice gender categorization between the Advanced Combination Encoder (ACE), a widely used clinical strategy in Nucleus® recipients, and STEP for fundamental frequencies (F0) 120–250 Hz. In the second experiment, loudn ess was determined as a function of the input amplitude of speech samples for carrier rates of 1000, 500, and 250 pps per channel. Then, using equally loud soun...