The effect of enhancing the spectral contrast of clean and noisy speech on intelligibility and listening comfort in hearing-impaired listeners is explored. Spectral contrast refers to the difference between the amplitude of spectral peaks and valleys in a short temporal window. A method of enhancing spectral contrast similar to that suggested by Bunnell [H. T. Bunnell, J. Acoust. Soc. Am. 88, 2546–2556 (1990)] was implemented in a simulated hearing aid with fast acting multiband wide-dynamic-range compression. The aid’s frequency response was adjusted to accommodate the individual listeners’ hearing losses. The effect of several degrees of spectral contrast enhancement on phoneme identification in quiet and in the presence of speech-spectrum-shaped noise was measured. In addition, listeners’ preferences for several degrees of spectral contrast enhancement were assessed in an A/B comparison of spectrally enhanced connected speech in quiet and in the presence of cafeteria noise. The experimental results will be reported and their implications for the use of spectral contrast enhancements in hearing aids will be discussed.