We recorded neural activity in the brains of freely-moving rats while they performed behavioral tasks for food reward. Neuronal responses to sounds depended strongly on the behavioral state: responses during behavior had more task-relevant information than responses during passive listening. Surprisingly, we also observed slow firing rate modulations that were task-related, not associated with sounds, and substantially larger than the sound-evoked responses. Modeling suggests that the large task-related rate modulations shape sound-driven responses during behavior. I will describe approaches for analyzing the fine-grained behavior of the animals and for deriving hypotheses about the nature of non-auditory, task-related activity.