Dragonlady2 makes a fair point about the broom test. For the grey in Madison, the random start is what would worry me too, so sticking to a set schedule while you're home sounds sensible. Have you tried running it in the other room first with the bird able to retreat to a familiar spot? I'd watch whether he settles within a few minutes or keeps pacing. Also worth noting whether he reacts to the motor or the cage bump more, since that tells you if a quieter model would even help.

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Dragonlady2 makes a fair point about the broom test. For the grey in Madison, the random start is what would worry me too, so sticking to a set schedule while you're home sounds sensible. Have you tried running it in the other room first with the bird able to retreat to a familiar spot? I'd watch whether he settles within a few minutes or keeps pacing. Also worth noting whether he reacts to the motor or the cage bump more, since that tells you if a quieter model would even help.