The Space Station Biological Research Project (SSBRP) at NASA Ames Research Center is developing rodent habitats that will be used to conduct long term mammalian gravitational biology on the International Space Station. In order to supply habitats to the research community that will provide a suitable living environment for the rodents, the SSBRP is conducting requirements definition studies to determine appropriate hardware development specifications. One such study has been to determine the maximum sound pressure level to which rats may be continuously exposed without adversely affecting their physiology or behavior. Male Sprague-Dawley rats were exposed continuously to white noise of 75 dB (SPL) within the 16 kHz octave band for 60 days. In addition to monitoring body weight, food and water intake, and behavioral observations throughout the experiment, a stress assessment battery and a determination of hearing ability were performed at the conclusion of the exposure.