Many animals will not do normal behavior, or stay quiet seeming calm as try to hide sickness. Ringnecks are extremely territorial and need lot of room if you have more than male female pair. If there are cages full that are quiet, they are stressed from shock of brought out of home etc. Not saying they were treated bad at all, just that they are not normally silent at all as my show stock various color morph ringnecks were never quiet even when caged covered etc. It's interesting sound but a healthy male will do from sun up to down and lot longer, when he isn't eating drinking sleeping. That's all ringmecks are basically bred for over thousands of years of siblings mated together to just produce look colors sounds and to breed more, in cockatiel cage per pair at most usually.