Responses of auditory neurons to a repeated, stimulus tend to decrease, but often the decrease does not generalize to other, even rather similar stimuli. These effects have been studied mostly with pure tone stimuli, although they are also present for complex stimuli, and we have named them stimulus-specific adaptation (SSA). SSA may however be a misnomer, because the specific reduction of the responses to a complex stimulus may be driven by frequency-specific adaptation to its frequency components, so that SSA could be in fact an expression of frequency-specific adaptation (FSA). Here I will discuss critical tests of FSA and SSA in the inferior colliculus and in auditory cortex, suggesting the emergence of SSA in cortex from FSA in the inferior colliculus.