I have kind of a wild, off-topic thought on sounds, inspired by reading Fnerg's post. This is not in any way a criticism or suggestion for the AH P-51, just an idea for the medium to long term future.
What if engine sounds were created by simulation instead of by recording RL planes? Build a simulated aero engine, with all the right cylinder sizes and placements, firing order, each little combustion, exhaust size and shape, etc. to simulate the physics of the engine sounds being produced.
I see the following advantages for flight sims:
- Sounds can be created in your basement, no need to go out and record actual aircraft, the model can even be used to synthesize sounds for engines that don't exist in running condition any more, as long as you know the physical parameters
- Model can be endlessly tweaked and improved until you and customers are satisfied without the need to go out and re-record in higher fidelity or whatever
- Any mode of engine operation can be simulated including those not practical to sample in RL (a P-51 engine at 30" and 2400 rpm sitting on the ramp does NOT sound the same as one flying at 300 mph and there is no good way to record the latter)
- Iterative testing would teach a lot about what really matters in simming engine sounds, e.g., does the accuracy of the individual cylinder firing sound really matter or is the sequence and timing in which it is played much more important
And I see drawbacks
- It would take a long time to develop the basic model
- Sounds might have to be compiled into the same looping audio files we are used to because of sim limitations rather than being real-time dynamic in-game
- Some might complain that the end product sounds too synthetic, like in music synthesis where there are some who believe that to synthesize a violin, you still have to start by going out and sampling a real Strad
In a quick google, I see that there are people working on this, especially for driving sims, and even a few commercial products out there. Some of these do not really try to model the engine physics to generate the individual component sounds, e.g. one cylinder firing, but they use algorithms to combine those sampled or otherwise generated sounds for the most realistic effect.
https://www.youtube.com/watch?v=7APK2RuTzZc
https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8574&context=masters_theses
http://tsugi-studio.com/blog/2018/05/01/real-time-synthesis-of-engines/
August