Tortoises get water from the plants they eat, but they also need to drink free-standing water to hydrate themselves. Within a few hours or minutes of rainfall, they will dig water catchments or go to natural places where water collects in boulders to drink. Desert tortoises can live to at least 80 and perhaps well over 100 years old. I understand that tortoises can vocalize. Studies indicate that tortoises may have both fear vocalizations and distress calls.
Males tend to grunt when mating.
They may also elicit sounds that we don't know about because they are either too high or too low for our hearing range. All of these prey on juveniles a very popular snack for desert dwellers. Older tortoises are also food for golden eagles, and, in the Sonoran Desert, perhaps mountain lions. That's surprising, since they seem like such hardy creatures. Certainly urban development, roads, and expanding agriculture destroyed much of the tortoises habitat and brought threats to the individual animals in the past.