Dr. Middlebrooks directs two NIH-funded research projects. One, on spatial hearing, explores the auditory cortical mechanisms that enable a listener to pick a sound out of a complex auditory scene on the basis of the sound’s location. Ongoing experiments comprise psychophysical studies in humans and cortical physiological and behavioral studies in animals. Recent experiments have demonstrated that the spatial selectivity of cortical neurons can sharpen dramatically when an animal is actively engaged in a sound-localization task compared to when it is idle and that single cortical neurons can synchronize selectively to one of two sound sequences from closely separated locations under conditions in which a human listener would report hearing two segregated “streams”. The other project, on auditory prosthesis, is developing the next generation of technologies for delivering electrical stimulation to the auditory nerve to restore hearing to profoundly deaf people. Ongoing experiments are aimed at translating the present results in animals to the first human trials.