Little is known about the acoustic behavior of Alaskan beluga whales, as their vocalizations have not been fully cataloged. Alaskan belugas summering in different regions are assumed to constitute distinct populations, but uncertainty remains about where to draw stock boundaries. Geographic variation in bioacoustics refers to dissimilarities in vocalizations between isolated, noninterbreeding populations of the same species. It occurs in many avian species and several mammalian species, and has been suggested for beluga whales in Russian waters. Geographic variation represents local adaptation and may lead to the development of new species. It is therefore important in conservation biology and management and should be considered in stock designation. Beluga whales from Bristol Bay and the Beaufort Sea are believed to constitute distinct stocks, but the extent to which they interbreed is unknown. A preliminary analysis of genetic distance between these putative stocks indicate genetic exchange is rare. This study characterizes and compares the vocal repertoires of these two populations. The data contribute to our understanding of beluga acoustic behavior and may contribute to the development of a noninvasive tool for elucidating stock structure in beluga whales.