Yeah, older ones had some issues with the blade geometry iirc which caused a fairly penetrating "Wump" noise which people complained about. There's a big one in

Yeah, older ones had some issues with the blade geometry iirc which caused a fairly penetrating "Wump" noise which people complained about. There's a big one in the town I live in, and people were complaining that the low frequency noise it was generating was impacting quality of life. I presume that's something which has been optimised away with newer designs?