Relations between objective intelligibility scores, subjective pleasantness ratings, and estimates of the STI for speech processed by multi-band amplitude compression systems were studied in normal-hearing listeners with simulated hearing loss. STI estimates were based on modulation spectrum changes in the processed speech signals [Payton and Braida, J. Acoust. Soc. Am. 106, 3637–3648 (1999)]. Linear amplification and two syllabic compression conditions were tested with and without two backgrounds: Speech-spectrum noise and restaurant babble. Signals were compressed independently in four nonoverlapping frequency bands with compression ratios of two and three, and attack and release times of 20 and 200 ms, respectively. The NAL-R formula determined output frequency-gain characteristics. Flat, 50 dB, sensorineural hearing losses were simulated in normal-hearing listeners via multiband expansion [Duchnowski and Zurek, J. Acoust. Soc. Am. 98, 3170–3181 (1995)]. Speech intelligibility and pleasantness ratings were obtained. All conditions were also evaluated using the modified STI. The STI predicted speech in restaurant babble would be more intelligible than speech in noise for each compression condition. The data reflected this for the two compression conditions. The STI predictions were also consistent with pleasantness ratings: Linear amplification was the most pleasant compression condition. [This work supported by NIDCD.]