Harvey Fletcher describes his work at Bell Labs from 1916 to his retirement in 1949 as Director of Physical Research. Discusses his relationship with Robert Millikan and his graduate work on the oil-drop experiment, acoustics work at Western Electric (later Bell Labs), including work on an underwater sound detector made for World War I. Describes his pioneering work in audiometry including physical measurement of audition, loudness of complex sounds, high quality transmission of speech, and music. Interview conducted by Bruce P. Bogert, a fellow acoustician and Bell Labs staff member.