Frederickson C J, Gerken G M
Science. 1977 Dec 23;198(4323):1276-8. doi: 10.1126/science.929201.
When pure-tone acoustic masking stimuli of various frequencies were presented simultaneously with electrical stimuli applied to cochlear nucleus, only those maskers within a limited frequency range interfered with the detection of the electrical stimuli. The form of the masking functions obtained suggest that the electrical stimulus directly activated only a small population of neurons which were functioning in a tonotopic fashion.