Dogs in animal shelters are subjected to a number of stressors during their stay, including barking which can reach 120 dB. Music has been suggested as a way to reduce this stress, however, the properties of music that result in reduced stress behavior have not been examined. An affective response to music, like that found in humans, is unlikely due to human higher cognitive function. Masking, reducing the magnitude of volume change with the presence of another sound, is one property that may be responsible for this observed stress reduction. Using white and pink noise, we examined the effects of auditory masking on stress behaviors in shelter dogs. Overall, we observed no difference in the amount of sitting, lying, head resting, or barking between the control and treatment conditions. Limitations and future directions of studies are listed.