The “Complete Theory of the Inverted Telephone Call” by Sydney Brenner:
As you know, when a telephone call is made its polarity is taken for granted; somebody is calling and somebody is receiving. How can this polarity be inverted? There is a simple form of inversion, well known to undergraduate students. You telephone your professor at 2 a.m. He answers, usually with burbling noises. You immediate say “Whom do you wish to speak to?” More noises — “What? what?” You then say “I’m sorry, you have the wrong number”, and you put the phone down, leaving them perplexed. For years I believed there was a complementary ploy, and in retirement I discovered it. When your telephone rings, you lift it and instantly say “May I please speak to Susie?” Usually there is a stunned silence but sometimes spluttering noises may be heard. You then say “I am terribly sorry, I must have the wrong number”, and immediate replace the receiver, leaving the caller confused and puzzled.
Current Biology 1995, Vol 5, No 6, p. 694