An acoustic reflex method of establishing hearing aid gain settings for most comfortable loudness was tested. Forty hearing-aid users were examined to determine relationships among MCL. loudness discomfort level, and the contralateral acoustic reflex to speech, under unaided and aided conditions. Results indicate that a simple 2-part rule results in amplification to most comfortable loudness for 76% of subjects. Implications for establishing hearing aid saturation sound pressure level settings are discussed.