On trains, it does. And people talking on the phone in designated silent carriages, as some operators have, enrages me. I am usually meek, but if someone starts yapping in a Silent Carriage I march up to them, point to the prominent No Mobile signs, and indicate they should talk in the corridor. With bad grace, they do.

On buses, it's different, and I'm much more tolerant. For a start, inside a bus is noisier than the church-like atmosphere of a train, so every word isn't broadcast to everyone on board.

And secondly, people on buses are less prone to being pompous. Long conversations about meetings and clients and cases --"and would you tell Trish I need the minutes tomorrow morning, pronto" -- these don't happen on buses.

Instead, well, this week a girl settled down for a long call to her boyfriend. She talked about which of them had fallen in love when, and how. She talked about the ups and downs of their relationship. There was a sudden silence and I knew he had said something amorous_. I thought to myself: I don't mind conversations, but if they're going to have phone sex then I'm throwing myself out of the emergency exit.

Luckily she didn't respond in kind, and they just talked on, for twenty minutes or so. I didn't mind because it wasn't intrusive, I read the paper through half of the call. It didn't grab the attention, as conversations do on trains.

And then the other day there was the guy, on the bus talking on his mobile about his curfew conditions, and his tag, and when he had to sign on at the police station. He sounded nice, it was all inoffensive, I went back to my book.

Then my theory that bus conversations are less intrusive was blown apart.

Yesterday the bus stopped unexpectedly, mid-route. The driver turned the engine off, and in the perfect silence someone answered their phone. The whole bus, the whole county, listened to every twist and turn as the person with the mobile described her relative's health, and her holiday plans, and some casual racism thrown in.

Reading was impossible.

It was horrible.

I've discovered there is nothing special about buses and phones. It's just buses are so wonderfully, so blissfully, noisy.