Unwrapped, erected, turned and obeyed.
Unit has correctly switched on screaming and transferred, but there was a constant loud "hum", humming to hear beep, which was usually louder than the baby. Only when the baby was screaming very loud, it drowned out the beeping. The beeping was just too loud and annoying, so we gave the baby monitor back. Channel change, other installation locations, closer together, further apart ... has brought no improvement.
It was the first baby monitors which we have listened to us and I hope we find one that can meet our needs. This certainly did not.