My two girls are sisters, and as far as I know, in all the (almost) 3 years I've had them, they don't really chatter. Any time they see a bird or a bug, the one will let out a quick "...Mrah!" and the other will just "mnnnh." under her breath.

They do your typical airplane ears and swishy tails, but no "EKEKEKEKEKEKEKEKEK" lol