IF, in years to come, historians want to describe the sound of the early twenty-first century, it won't involve guitars or drums, Darkness, Beyonc or even the wealthy Miss Church.

The sound they'll want is the bleep. Everything bleeps.

Phones bleep as we key in numbers. Keypads on holes-in-walls (known as cash dispensers on Sundays) bleep at our PINs. If we don't switch the sound off, mobile phones bleep with every letter of a text message as well as when we ask them to come up with a number, and then they bleep pathetically to let us know their batteries are about to die.

Lorries bleep as they reverse, which is, I have to say, marginally better than the monotonous metallic voice which says endlessly: "Vehicle reversing."

Kitchen timers bleep, so do smoke alarms. Our car burglar alarm bleeps once as it goes on and gives four silence-shattering bleeps as we switch it off.

Even my travel alarm bleeps now, as the only sort I could get to replace an ancient, wind-up, bell-ringing model was battery-operated.

But even more annoying than the ubiquitous bleep is the unidentified bleep. Unidentified bleeps are just plain unnerving.

There I was, the other day, dusting the banisters and thinking about anything and everything except the dull job in hand when a solitary bleep cut into my daydreams.

Just the one. Most bleeps hang around in groups so I stood still and waited for its mates to follow. Nothing.

It couldn't have been the smoke alarm starting to ask for a new battery as that was just above my head. The carbon monoxide alarm? No, that would have carried on at an ear-aching pitch. So would the burglar alarm, which wasn't active at the time and, if it had been, it would have asked me for the password within seconds of being disturbed.

The e-mail phone? It doesn't go in for solitary bleeps, but I might have missed the first two in the depths of thought. No, the screen was dark, so nothing doing there. The computer? No, because, even when it is switched on, we don't have the sound activated. Mobile phone? When I tracked it down, that wasn't switched on either.

We haven't got a microwave; the washer goes about its business with no more than rumbles; I wasn't timing anything in the kitchen, and I hadn't got a radio on.

In the end, after a top-to-bottom search of the house, I decided that, as the place obviously wasn't on fire, being burgled, or filled with carbon monoxide, it could just remain one of life's little mysteries and a waste of a good ten minutes. I went back to dusting the banisters.