Average discharge rate of single auditory‐nerve fibers in cats was measured in response to one‐ and two‐tone stimuli. One component (the ’’suppressor tone’’) of each two‐tone stimulus was at a frequency (f2) which produced two‐tone suppression at some stimulus levels. The other component (excitor tone) produced an increase in rate above the spontaneous rate when presented alone. Fractional response was defined as the driven rate to the two‐tone stimulus divided by the driven rate to the excitor alone. Fractional response is thus a quantitative measure of the amount of suppression produced by a suppressor tone. A number of qualitative differences were found in the dependence of fractional response forf2≳CF andf2