Introduction: My long term research goals are to understand how complex sounds are processed by the auditory system and to determine how age-related hearing loss impacts this processing. Many animals, including humans, use species-specific vocalizations to convey biologically important information to members of the same species. These vocalizations are often complex in frequency and time. A fundamental function of the auditory system is to process these complex sounds. How complex sounds are processed and represented in the auditory system is not understood. My research focuses on characterizing the neural mechanisms that underlie encoding of complex sounds. The main focus is on the main auditory midbrain nucleus, the inferior colliculus, but we are also conducting studies on the dorsal cochlear nucleus and auditory cortex.