When communicating vocally, they have four different types of whistles, differing in this from their close relatives, the hoary marmot and the Vancouver Island marmot. The Olympic marmot's whistles include flat calls, ascending calls, descending calls, and trills; all of these are in a small frequency range of about 2,700 Hz. Flat, ascending, and descending calls are most often voiced singly. The ascending call has a duration of about half a second, starting with a yell on one note and ending with a chip on a higher note; it is often used as a distress or warning call for unfamiliar smells and noises. These same yips are heard when Olympic marmots are play fighting, along with low growls and chattering of teeth. The descending call ends on a lower note than the one on which it started. The trill, which sounds like multiple ascending calls put together as one longer sound, consists of multiple ranging notes and is voiced as an alarm call to communicate to other marmots in the area that danger may be approaching and they should return to their burrows. Females with young have the responsibility to watch out for their young and other relatives near the burrow, and therefore voice the trill more often than other Olympic marmots. If marmots are not accustomed to human contact in a certain area, they may also sound a trill when seeing a person, in order to alert other marmots. At places like Hurricane Ridge, where seeing humans is a frequent occurrence, most marmots will not acknowledge human presence at all.