Frequency of boy-time: eh, varies by hedgehog, mood, season, colour of the food, scent wafting on the air... My little friend has gone through periods of intense activity (nightly, or more than once a night), and periods where either he isn't at all, or he's hiding it really, really well.
Noisy: no idea. Sudden onset of squeaky breathing can be an early URI symptom? Some hedgehogs are quite vocal sleepers, though, some even screaming from little hedgie nightmares.
So could be normal, could be substantial change in behaviour that is an early warning sign. No direct experience, so please let other voices overrule me!
