Neural responses elicited by stimuli associated with masking of low-frequency, monaural tonal signals by noise

The responses of low-frequency, primary-like neurons of the ventral cochlear nucleus were measured as a function of signal-to-noise ratio for gated tonal signals and noise maskers that were varied in bandwidth and duration. For a given signal-to-noise ratio, each of the maskers is known to produce the same amount of masking in psychophysical experiments. The neural discharge rates measured in the present experiment were different, however, for each of the maskers for each signal-to-noise ratio. In contrast, all three maskers produced the same orderly relationship between signal-to-noise ratio and the degree of neural synchrony to the signals. It is concluded that information concerning the presence and relative strength of a low-frequency tonal signal in a background of masking noise is carried by the nervous system as the degree to which responses are synchronized to the phase of the signal.