The test of Speech Perception In Noise (SPIN) [D. N. Kalikow, K. N. Stevens. and L. L. Elliott, J. Acoust. Soc. Am. 61, 1337–1351 0977)] results in two scores for a subject—the percent-correct identification of low- and high-probability items, denoted PL and PH. A basic problem is to derive from these raw scores appropriate metrics which characterize a subject's abilities (a) to make use of context, and (b) to hear speech in noise. Examination of the PL and PH scores (averaged across all ten forms) for 128 subjects with sensorineural hearing loss suggests that normal-normal-probability space may be a useful coordinate system for characterizing these abilities. In this space, the extent to which the subject makes use of context can be associated with the difference d between the Z scores associated with PL and PH, i.e., d = ZH − ZL. Additionally, the overall ability of the subject to hear speech in noise can be associated with the quantity κ = −(ZH −ZL)/2, which is independent of d, and which can be transformed back to an equivalent “percentage-hearing” score. [Work done under contract to NINCDS.]