Airfix1001
I couldn't really say how the noise of a bus 30ft away compares with the A319 or ATR72 I'm afraid. The reason I carried out my 'experiment' on Jersey was simply because I couldn't believe the noise horror stories being put out by the SEN objectors and my own observations proved them to be totally false.
As far as the ATR72 sounding noisier than the A319 is concerned, I expect it will actually sound slightly quieter. The ATR72-200 (which Aer Arann will be basing at SEN) is certificated as being 5.70dBA quieter on approach than is the ATR42-300 I monitored at JER - which illustrates the point that the more modern the aircraft the quieter it is likely to be.
Noise is also a subjective matter depending on the pitch and frequency of the noise - personally I found the 'sound' of the A319 more pleasant than that of the ATR42-300 but I'm sure that's a personal thing. Do keep an eye open for the A319 at SEN because at the moment Easyjet aircraft are visiting for resprays - one landed at 07:30 yesterday but not from your direction I believe. I'm sure if you 'phoned the airport after any particular aircraft has passed over you on approach they would tell you exactly what it was. That way you can judge for yourself.