Very noisy and rackety! But not as bad as rainbow lorikeets or juvenile pink and grey galahs. Carnaby's cockatoos tend to make the most of their racket in flight, and it's an amazing, piercing, 'WEELAH! WEELAH!' sound, that they all make together. It's hard to explain why that's so awesome, but I find it a very inspiring, uplifting sound; as opposed to rainbow lorikeets which are extraordinarily shrill and painful.