Having just endured nights of buzzing motor scooters in Turin, can anybody explain what it is about the sound that irritates me so much but seemingly does not bother Italians who are used to it?

Peter Smith, Leicester, UK

I've heard that your brain calculates the position by the time difference between the sound reaching one ear and the other. However, i'm sure this is wrong! If there's a loud bang a short distance behind you, how do you know it was behind you? The sound would reach both ears at the same time, so the source could be infront of you, or even above you!

Sometimes I don't hear a plane until it makes a loud, sudden, decelleration sort of sound - which I describe as it dropping out of warp - and then just normal jet-like noises after that. Before that, silence! So how? Why don't I hear the plane until that point and what creates the noise? I tried to google this but was unsure how to spell 'beewooooooo' to get the right response...