The dorsal cochlear nucleus (DCN) is an initial site of central auditory processing, and also the first site of multi-sensory convergence in the auditory pathway. The auditory nerve imparts a tonotopic frequency organization on the responses of principal cells in the DCN. Cartwheel cells modify the responses of principal cells, but they do not receive direct auditory nerve input. This study shows that cartwheel cells respond well to tonal stimuli in the awake mouse, and they have a well defined characteristic frequency that corresponds to the tonotopic organization of the DCN. The auditory responses of cartwheel cells exhibit complex spectral-temporal responses to tones, with excitation and inhibition modulating the firing patterns in both frequency and time following the onset of the stimulus. Temporal responses to best frequency tones are highly variable between cartwheel cells, but a simple model is used to unify this variability as differences in the timing of synaptic currents. Cartwheel cell responses to two-tone stimuli show that interactions from different frequencies affect the output of cartwheel cells. The results suggest that at this primary auditory structure, processing of sound at one frequency can be modified by sounds of different frequency. These complex frequency and temporal interactions in cartwheel cells suggest that these neurons play an active role in basic sound processing.