Why does my Dyson ball 25 make Loud deep whistle sound on start up

Starting up my Dyson ball has a deep almost whistle sound for a few mins after starting up. When it shuts off it literally sounds like a jet fighter engine spooling down.

Only thing I can sugest is a seal on something or a bad gate when I switch from using the wand to push mode. Maybe something didn't close. It partially goes away while using it.