Silent skies

If only I'd gone to Windsor Great Park this last weekend rather than a few weekends ago - a lovely afternoon marred only by the roar of Boeings and Airbuses flying overhead every few minutes on their way to land at Heathrow.  Now the skies are empty and clear, thanks to Mt Unpronounceable's eruption in Iceland.

It's not that the skies are empty; it's that they're quiet.  I've got a hunch, based upon nothing more scientific than my own ears, that the quiescent noise level has dropped by a good few decibels the last few days, even in central London, even on busy roads.  Marylebone Road sounded quiet - well, quieter than usual, at least - yesterday evening (of course, this could be because there are fewer cars driving to the airport!).

Is it possible that constant air traffic over major urban areas, such as London, has raised the entire noise floor of entire cities?  Walking down the street outside of major flight paths, one doesn't generally listen to individual aircraft.  But does their presence in an area, coupled with the omnidirectional propagation of sound waves from a height of a few thousand metres, create a constant background noise that we've all learned to ignore?

If you're reading this and are in the no-fly zone, go to a park and enjoy the silence while you can.