The voice: barely there
Measured purely as vocal noise, a hedgehog is one of the quietest pets you can keep. Their sounds are small ones: soft huffs and puffs when startled, clicking when annoyed, snuffling as they explore, and the occasional squeak from a youngster. There is no call, no dawn chorus, nothing designed to carry. A hedgehog in the next room makes less vocal noise than a ticking clock. A hedgehog heard clearly across a room is usually announcing annoyance, not making conversation.
The surprise is that the animal attached to that quiet voice leads a very busy night — and it is the night, not the voice, that you hear.
The night shift is the soundtrack
Hedgehogs are built to travel: in the wild they cover serious ground foraging, and a pet hedgehog does its travelling on an exercise wheel, at speed, for hours, in the small hours of the night. A wheel with any wobble or squeak becomes a rhythm section. Around it sit the other sounds of industry: digging and rearranging bedding, crunching through food with real enthusiasm, the rattle of a water bottle, and the thump of a small animal reorganising its house. Even the drinking joins in: a ball-valve bottle clicks with every sip, and a hedgehog drinks often through the night.
None of it is loud in raw volume. All of it happens at three in the morning, in a silent house — which is exactly when small sounds loom largest.
Placement beats soundproofing
The practical answer is geography, not training; you cannot ask a nocturnal animal to keep office hours. A hedgehog in a living room, hallway or spare room is, for most households, effectively silent. A hedgehog in a light sleeper's bedroom is a nightly event. A good solid-surface wheel, sitting level, removes the squeak; deep bedding muffles the digging; and a household that runs a dishwasher overnight will never hear a hedgehog at all. A folded mat beneath the enclosure also deadens the small vibrations that otherwise travel through floorboards into the room below.
Warmth plays a part too: a hedgehog kept properly warm settles into steady routines, while a cold one becomes restless in ways that help nobody's sleep.
Night sounds that should wake you up
Learn the short list of sounds that are not routine. Loud squealing is a pain or distress call and means checking the animal straight away. Persistent sneezing, wheezing or bubbly breathing suggests respiratory trouble. Frantic, repeated scratching through the night can point to skin irritation. Any of these, continuing, belongs in front of a vet with exotic-pet experience rather than on a wait-and-see list.
Ordinary nights reduce to a judgement call most owners make within the first fortnight: wheel noise, fine; new noise, investigate. When the sound you just heard still will not settle into either camp, put a follow-up question to KinsLe's Kinny; he answers using the KinsLe Answers library.