Nanohedron wrote:
benhall.1 wrote:
On that recording, the sound was perfectly obviously meant to imply a helicopter, but what I meant was that it may not actually have been the sound of a helicopter. It sounded a little too rhythmical to me. But it could have been, of course ...
Sounded real enough to me, so if it's not a sound sample, that was a darned good job. I can't imagine any drum could approach that level of fidelity, though.
I've listened carefully again, and I am convinced that I am right on this one - not that it's necessarily a drum - in fact, now that I've listened a few times, I'd say the chances are very strong that it's an electronically produced sound - but I really don't think it's an actual chopper. There are three things that persuade me it isn't, apart from the general sound of the thing not being quite 'right', at least to my ears:
Firstly, as I said before, it's too rhythmical. With a real helicopter, the sound doesn't quite follow a regular beat, and this one does.
Secondly, there's a deep, bass, scrapey, sort of 'parp' sound that a real helicopter makes with each 'beat' of the props. It's absent from this recording.
Thirdly, there is virtually no Doppler effect present at all. The tone changes a bit, in what to me seems an electronic sort of a way, but the pitch hardly changes at all. I've never heard a helicopter where the pitch doesn't change constantly. Either it's manoeuvring, in which case the sound changes fairly dramatically and will rise and fall in pitch, or it's flying in a straight line, in which case there will be a distinct Doppler effect and the sound will drop off in pitch considerably.
Having said all of that, I've never been in a helicopter - I've heard plenty, but never been up in one. I've heard the sound in plenty of films, of course, and the pitch always varies dramatically in them, but maybe that's for dramatic effect. Maybe the pitch is constant if you record the sound in a helicopter, flying at a constant height, at a constant speed, in a straight line and with constant wind speed.