A summary of the noise in the kitchen would be -
Smashed ceiling lightshade.
Two knocked over chairs.
One knocked over stool.
One knocked over sugar bowl.
Silencer scraping the aga.
Moved but not knocked over furniture. Maybe the kitchen table.
Bamber's footware may make a noise on the kitchen floor.
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Estimated time of attack, 60-90 seconds.
The blows to Nevill's head, face and torso would not make a noise.
I don't believe any of the above would be particulary loud or long enough to wake Sheila upstairs. But possible.