Depending on the type, a rabbit may grunt, snort or scream. For the most part, they are quiet animals that do not make a lot of noise.
Many people compare the noises that a rabbit makes to those of a guinea pig. When they are not happy with a situation, they will grunt or snort. In times of extreme pain, they may scream loudly. However, this sound is very rare. as pain of that type often leads to their death.
In addition to sounds made while awake, rabbits may also snore while they are sleeping. It sounds similar to what you would hear from a human, only softer.