Background music. Tons of these streams on youtube. Some are two hours, lots are continuous. Usually good to find some that have percussion to mask device sounds.
Earbuds with tight fitting eartips, if you want it even better throw a pair of over the ear headphones on top of the earbuds. Easy to try if you have them around.
Sound absorbing panels - Can be decorative too.
https://www.ebay.com/itm/192823826020?hash=item2ce5321664:g:1PwAAOSwtYxZgehC
Someone mentioned a comforter, could be good to hang over a door as well.
Loose sleeves and thin lube lessens the device load. (well prob not on the original posters Kiiroo / Hot Octopuss Pulse Solo Interactive) lol.