s medical school before moving to the NIH in 1967. Early in his career at the NIH, he worked on the higher auditory systems of New and Old World primates. His publications during this period covered reticular activation of auditory cortex, the role of auditory cortex in perception of temporal patterns, coding of species-specific sounds in thalamic and cortical auditory neurons, and discrimination of vocal variants in behaving monkeys.
His later work involved correlations between vocal and social behavior, the functions of interindividual and intraindividual structural variability in calls, mother-infant vocal communication in both humans and nonhuman primates, and the role of play behavior in development. He was particularly interested in the affiliative relationships of squirrel monkeys and the complex vocal communication that maintained them.
David was well-known for his skill in developing novel computer-based methods for analyzing primate vocalizations. While most of his auditory work was with squirrel monkeys, the vocal behavior of many other New World species, as well as macaques and humans, were studied through collaborations with his sound analysis laboratory at the NIH.
Survivors include his wife, Jean Sinclair Symmes, who is a clinical psychologist in McLean, and three children.