It's been a nice weekend in Edinburgh, but the journey back to King's Cross is as tiresome as always: packed into a seat every bit as crippling as one you find in the air, I try to negotiate my way through the newspaper without impaling my neighbour on my elbow. At least I don't have a large, wet and thoroughly odiferous dog sitting under my seat -- the treat the train company laid on for me on my journey up on Friday. At last, I lapse into a troubled doze, only to be roused every five minutes by one of a selection of mobile phone rings or the conversation that follows. To my sleep-muddled mind, it feels like being imprisoned with a collection of hyperactive, bleeping robots set on singing out then talking to themselves: a dawn chorus in Hades. Then it hits me -- the answer to the mobile phone ring tone conundrum. It's not the fact that mobile phones make noise that upsets us, it's that the noises are so darn intrusive and ugly. Likewise the conversation: humans are used to being in environments where others are talking -- just not ones where you can only hear one side of the story. So, changing the rules such that mobile phones behave in a way that we're programmed to accept, and the problem goes away. We evolved, so it's thought, in an environment with lots of trees and veldt-like plains, shared with many other creatures. Of these, the noisiest are the birds, which rarely miss a chance to fill the air with song -- and us humans are well-disposed towards the sound. Put even the grumpiest curmudgeon in a sun-dappled forest filled with feathered symphonies and happiness ensues. Thus, now we have the technology for mobiles to play samples instead of synthesised bleeps, it should be compulsory for them to issue forth sweet birdsong. There are tens of thousands of species that make acceptable noises, so there'll be no need for clashes, and the morning train will come to resemble a haven of bucolic tranquillity. As for the one-sided conversation: make the phones hands-free only. That way, we'll all hear both sides of the talking, and people on the phone will instinctively be circumspect, quiet and brief. Even if it's still a bit annoying, it'll be a lot more interesting.