Could monaural loudness adaptation be a simple artifact of psychophysical c
ontrast? From adaptation data based on the Ipsilateral Comparison Paradigm
(ICP), A. J. Dange, J. S. Warm, E. M. Weller, and W. N. Dember (1993) concl
uded that loudness adaptation was not an artifact of psychophysical contras
t, but their conclusion was dependent on results from one intensity. This s
tudy, involving multiple intensities, re-examined the issue of contrast ver
sus adaptation and generally supported the conclusions of Dange et al. The
results also showed an unexpected asymmetry of adaptation based on the dire
ction of the referent modulation used with the ICP technique. Some implicat
ions are discussed.