On 7/17/07, Maik Justus <[EMAIL PROTECTED]> wrote: > > If it _is_ a doppler > > effect, it's wrong. > Absolutely! What is interesting, that not all aircrafts have this effect. > Maybe this is only with aircrafts with more than one sound source and > what we hear is just the position dependence of the sound mixing? > While moving the external-view camera we get real Doppler effects; > realistic, but maybe confusing. This could confuse our ears, too.
I didn't think of the mixing of two sound sources, that's a possibility. I think the doppler effect while moving the camera is fine, of course. > I think, that after moving the external camera I sometimes hear "wrong" > pitch. Switching then between external views, the "wrong" pitch is > constant. But moving to cockpit view and back to external view "resets" > the pitch to normal. Strange. Could this be the phase shift between the > two engine sounds? Switching to cockpit view switches the external > sounds off and switching form cockpit view to external view switches > them on without phase shift. Moving the external camera causes some > Doppler Effects (resulting in a phase shift of the two identical jet > sounds played with identical pitch). I think 787 and Bravo uses the > jet.wav sound. I tried to play this sound twice with some phase shift > and I think I get the same. That sounds like the best theory to me. Incidentally I observed a similar effect in real life the other day while watching my brother in law doing some patterns at the airport. I had my really-cheap one-speaker handheld static-spewing airband radio tuned to ATC, and as I walked away from the radio the obvserved pitch of the static (white noise) rose. I'm attributing it to the lowpass nature of sound traveling through air, or maybe some sort of positional effect from the acoustic properties of the speaker projection. It was an odd coincidence to observe that on the same day as reporting this though. :) > > The second observation is in flyby mode, and has to do with > > directional sound. I notice that when the plane is flying almost > > directly toward the observation point, the sound still comes full from > > one side, and when the plane passes and heads almost directly away > > >from the observer the sound comes full from the other side. I have > > even observed the plane coming at a significant angle with the sound > > coming from the opposite side from what it should. It seems like the > > stereo effect is being applied in a simplistic way, rather than based > > on the angle between straight-ahead and where the plane is. > > > No, that should be correct/realistic, but maybe there is a bug. But I > was not able, to reproduce this bug here. Which aircraft you are using? > This could be the cause, if the aircraft is using a stereo sound file. > Which operating system you are running? There are some OS-dependencies > in the sound, but the stereo calculation is always done by OpenAL > itself. Can you check, if you have this effect with the A6M2, too? I can't figure out how to start the engines in the A6M2, or I'd tell you. (Oh, I just realized it was the spacebar/s switch. *tries again*) My computer can't keep up with this plane, so it's hard to say for sure, but I don't think I notice it. The plane I was using was the c172p. I'm on OSX. Listening again to the c172p with different (better) headphones, I'm not as sure now. It still seems like it but it's not cut and dry and might be a psychoacoustic effect (i.e. in my head). ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
