This amazes me; I must've gotten very very lucky. I'm extremely noise sensitive and have had 5 Tivos (3 S2s, 1 S3, 1 HD) and now a new Roamio - always in my bedroom and have never heard one unless I went and put my ear to it. Head of my bed is about 13' from the open sideboard the Tivos have lived on, i.e. they've not been behind closed doors. Two of the S2s were in a secondary residence with a smaller bedroom, maybe 8' from Tivo to bed headboard. I've replaced 3 of the hard drives, always with the one that was rated the quietest, so have had a mix of original drives and replacements. My new Roamio has only been in operation for one day but so far it's the same quiet experience as the others.