Any grounded ideas about hearing a shushing sound at night?

I’d start with ordinary sound sources: a neighbor through a wall, heating or plumbing, a device you hadn’t noticed, or a sound that gets interpreted as shushing in the moment. Try checking the room and nearby spaces when it happens, and jot down when it occurs. That may help reveal a pattern without assuming what caused it.

Waking suddenly or being very short on sleep can make sounds feel unusually vivid, especially around the edge of sleep. That doesn’t establish that this is what happened, but it’s one possible explanation. If you keep hearing it when fully awake, or it starts happening during the day or worries you, bring it up with a healthcare professional.

First, check that your child is okay and that there isn’t a sound source you can identify. If nothing turns up, you don’t have to settle on an explanation that night. Keep track of sleep and timing for a while, and ask a clinician if it repeats or becomes distressing.