Hedgehogs typically are quiet animals, however they do have quite a variety of sounds that they make when needed. Some of these noises may be caused by annoyance, fear, or happiness. Below is a list of sounds and their meanings to help you understand what your hedgehog is trying to communicate.
Whistling & purring: These are sounds of trust and contentment. Your hedgehog is comfortable and happy with his surroundings.
Snuffling: This sound can normally be associated with a hedgehog that is happily exploring his surroundings.
Snorting: Snorting normally is heard with puffing, and means the same thing.
Puffing: These are sounds of uncertainty and displeasure/distrust
Purring: This sound typically means that a hedgehog is happy and content.
Chirping/squeaking/singing: These sounds are very often heard when a male is courting a female, they are also very commonly heard from babies who are nursing.
Clicking & hissing: These sounds mean "leave me alone, I'm scared or tired of you".
Screaming: This is a sound of fear or physical pain. It is not a sound you should ever hear.
Hedgehogs have also been known to snore or make one or more of the above noises while sleeping. I have often wondered what my hedgehog has found in his dreams from the many sounds they make.