@86andcounting
As far as I'm aware, Sky Hubs don't contain any speakers: the most noise they can potentially emit is the whine of solid state electronics or the click of an electromagnet relay circuit.
I'd suggest temporarily pulling the Hub power supply out: if the beeping continues then you can be fairly sure it's not the culprit.
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Sky Glass 55" (on ethernet) & two Stream Pucks (one ethernet / one WiFi)
BT Halo 3+ Ultrafast FTTP (500Mbs), BT Smart Hub 2
