Yes taxi driver, sit there and press your horn. I’m sure the sound will pass right though all the surrounding buildings, missing out everyone but the intended target whom it will pick out with the accuracy a snipers bullet.
Oh wait, actually it’s everybody who can hear it. Apparently except for whoever it was that phoned for a taxi. And still you press the horn.
Heaven forbid that you should exercise your legs or brain rather than just honing that one mighty button pressing finger and take some other action to resolve this obviously bemusing situation.