The listening level chosen by a hearing aid wearer for receiving amplified speech in noise has a substantial impact on the benefit that the hearing aid can provide. Chosen listening levels determine (1) the extent to which audibility of speech cues is improved by amplification, (2) the in situ distortion generated by the hearing aid, and sometimes (3) the auditory resolution abilities available to the hearing-impaired listener. All of these variables have been shown to affect hearing aid benefit. Thus, to predict benefit in any particular listening environment, the listening level that the wearer would choose in that setting must be known with some precision. This paper reports two studies of chosen, or preferred, listening levels. We present evidence to show that preferred listening levels vary with changes in the listening environment, especially when the signal-to-noise ratio is favorable. We describe a method for predicting preferred listening level changes in some environments that differ in talker levels and or signal-to-noise ratios.