On departure they are quieter indeed. But on arrival the A220 and the A320neo family aircraft have a high-pitched whistling noise which is quite irritating. No clue if it's the flaps, gears on else but it usually starts on 1000-1200 feet and lasts for around 8-10 seconds. It's something like the famous Yak-40 "whistle" during engine startup. See the video at 01:11.