In the early days of telephony, before they had the good sense to invent the buzzer, or ringer, every telephone owner would have a specially bred telephone owl, which would sit on a perch at specific times of day to alert its master that someone was trying to ring them. The owl would watch the receiver patiently, until the little light flashed, at which point it would spring into action, swoop over to its  owner, who was perhaps in the next room, or at the foot of the garden, and say “twit-twit-twoo-twoo!”  and “twit-twit-twoo-twoo!” and then “twit-twit-twoo-twoo-twoo!”, at which point the phone owner would know there was a very important message and they would rush to the receiver and converse at a distance. If round-the-clock coverage was important, the owner may choose to have two owls working in shifts. And if no-one was home, the telephone owl would say simply “twoooo”, and then try as best it could to remember the message given to it by the disembodied voice, and then relate it to its master once they got home. Through mime.