William Hartmann received a BS degree in Electrical Engineering from Iowa Sate University and a D.Phil. in Theoretical Physics from Oxford University. In 1974, he began to teach musical acoustics, and he discovered how much fun acoustics could be. Two years later he began full time work in psychoacoustics, and he joined ASA. His work in human pitch perception led to the discovery of the binaural edge pitch, the pitch shift of mistuned harmonics, and harmonic unmasking. In 1981 he began a six-year association with the Institut de Recherche et Coordination Acoustique-Musique in Paris. There he began work on the human localization of sound sources in the presence of reflections from room surfaces. Dr. Hartmann has been an active member of ASA, serving as a member of the Executive Council, as vice president, and as president, 2001-2002.
Human listeners, and other animals too, use interaural differences to localize sound sources in space. Differences include the interaural time difference (ITD) and the interaural level difference (ILD). Listeners make use of ITD at low frequencies and ILD at high frequencies. This talk will discuss how the human binaural system is effectively an interaural time difference meter and not an interaural phase difference meter, and also that the boundary between low and high is the surprisingly low frequency of about 500 Hz.