The Swedish term "mumla, muttra" matches the English term "mumble"

other swedish words that include "mumla" : english :
mummel, sorla, knota, porla, mumla, susa murmur
mummel, mumla, muttra mutter
other swedish words that include "muttra" : english :
mummel, mumla, muttra mutter
muttra natter
tokig, nötter, muttrar nuts
sequoia, mammutträd sequoia