What changes the cockatiel questions answer
Track the time, trigger, and result. Morning and evening calls can be normal, but repeated screaming often means the bird is tired, lonely, scared, hormonal, bored, in pain, or has learned that screaming brings people running.
Fix the routine first
Protect 10 to 12 hours of quiet sleep, move the cage away from constant chaos, add predictable out-of-cage time, and give foraging or chew work before the noisy part of the day.
Reward the sound you want
Answer soft contact calls, whistles, stationing, toy play, and calm waiting. If screaming already started, wait for a tiny pause before you respond so the pause gets paid, not the scream.
Rule out health and fear
A sudden change in voice, appetite, droppings, posture, balance, or breathing belongs on the health list, not only the training list.
Do not make it louder
Yelling back, covering the cage as punishment, spraying water, or rushing in every time can make screaming stronger.