ABSTRACT
A variety of auditory functions depend upon information from both ears, or binaural hearing. It is interesting to mention that barn owls have an arrangement of neurons in the external nucleus of the inferior colliculus (ICX) sensitive to spatial locations that constitutes a topographical map of auditory space. Sensitivity to binaural information continues beyond the inferior colliculus to the auditory thalamus and cortex. The cortex responds to a variety of binaural stimuli, such as interaural level differences (ILDs) and interaural time differences (ITDs), and some auditory cortical neurons are also responsive to interaural differences in both level and time. Tuning curves providing best or characteristic frequencies (CFs) has been reported for the all levels of the auditory system from the cochlear nuclei through the auditory cortex. The tonotopic organization of auditory and auditory-related cortical areas has been studied in a variety animals for many years. The auditory steady-state response (ASSR) is evoked by signals that modulate periodically.
