In a novel I was reading the other week the author remarked on the intense anger and distress that can be caused by the repetition of relatively innocuous things. I thought of throat-clearing, ring tones and Graham Norton's face, and I agreed.

According to myth, Chinese water torture worked the same way: tiny drops of water were dripped at intervals on the victim's forehead until they caused him to go insane.

I thought of all this yesterday when I was exposed - as I am every morning and evening - to London buses' own form of Chinese water torture: the recorded voice that says "Bus stopping at next bus stop, please stand well clear of doors", advice which is repeated, with the remorselessness that only machines and small children possess, every time a request bell is pushed.

It's a slightly stroppy, high-pitched voice with a quaver in it - like a young teacher trying to hang on to her authority in a dangerously rowdy classroom. In that sense it is entirely appropriate for a London bus. But in all other senses it is completely inappropriate and unnecessary.

There are already loud bells and flashing signs to let you know the bus is stopping, I think people get the message just fine with them - and have done for years.

It would be nice to have the name of the person whose idea the voice was. It would give me "closure" to know my torturer's name.

I calculate I hear the voice on average about 30 times a day (four bus journeys). That's roughly 150 times a week, not counting weekends.

It might be more useful if the voice varied its advice, for example: "Truculent hoodie getting on bus, please stand well clear and avoid eye contact," or "This bus has changed its destination sign since you boarded and will be turning round' early, making you late for work."

Now that would be a useful warning.