Forward masking by enhanced components in harmonic complexes.

The ability of a given target component in certain spectral complexes can be considerably increased by exposure to the complex with the target component deleted. This "enhancement effect" can be observed under a wide variety of conditions and presumably reflects frequency-specific adaptation: the frequency region around the target frequency is not adapted during the exposure and hence is relatively more sensitive. Data from the present study indicate that an enhanced component in a harmonic complex produces more forward masking of a sinusoidal probe than when that component is not enhanced, i.e., an enhanced component behaves as if it were physically more intense. This suggests that the adaptation process underlying the enhancement effect produces an increase in gain in the unadapted frequency region. This increase might result from a decrease, due to adaptation, of suppression of the unadapted region.