Responses of auditory nerve fibres in the guinea pig to noise bands of different widths.

The responses of single fibres of the auditory nerve were recorded in anaesthetised guinea pigs. The fibres were stimulated by bandpass noise centered on the characteristic frequency. As the noise bandwidth was increased at constant spectral density, the firing rate increased, came to a peak, and in the majority of fibres, declined at wider bandwidths. The bandwidth at which the firing was at a peak had a mean value of 34% of the characteristic frequency. On average, the evoked firing rate was supressed by 8% at the widest bands of noise used. However, 17% of fibres showed no suppression at all. In those that did, suppression was still visible if the stimulus intensity was so high as to drive the firing into saturation.