Ceolán means an incessant talker, not incessant as an adjective. It also means a little bell or a small tinkling sound. It doesn’t seem to be a terrible choice given what the OP is looking for. It’s hard to find a word in Irish that doesn’t have multiple, often radically different, meanings. The word that sprung to my mind was “gligín”, which means several things, including little bell, tinkler, rattler, a jingle (like a piece of music you’d hear in advertisement), and rattle-brained person.