We sometimes get both flying overhead and the Heathrow flights are generally noisier than the City ones - I agree it will depend on exactly where you are in relation to the flight paths.
To further my recent point about noise from a plane, did not use the right phrase, it was about airframe noise. This is a significant factor on approach:
Airframe noise is particularly noticeable on approach, when propulsion and throttle-related noise sources are relatively low.
This is not from source I mentioned but this: http://www.noisequest.psu.edu/sourcesofn...rview.html
The upshot is we are getting to the point where little more can be done to reduce engine noise and airframe noise is going to hard to tackle, especially with large planes.