Preserving the formants while pitch-shifting

(Hagai Davidoff) #1


Is it possible?
I’m building a car engine and I’m using the auto-pitch modulator.
It doesn’t really sound natural to say the least, because it move the formants along with the fundamental…
Any ideas how to overcome the “chipmunk” effect?


(リチャード清水) #2

Hi Hagai,

You might want to take a look into the “Basic Engine” and “Car Engine” events in the FMOD Studio example project.

A single engine sound will have a chipmunk-y effect as the autopitch is literally just going to raise the pitch from the minimum pitch based on the root pitch, up to the parameters maximum value.

The ideal setup, as shown in both the example events is to have multiple overlapping engine sounds with altered root pitches to ensure they don’t pitch bend too extreme.

You can find more information on autopitch and the root pitch in our manual (press F1 with FMOD Studio open).


(Hagai Davidoff) #3

Hi Richard,

Thanks for your reply!

Of course I’ve looked into the examples. They suffer from the same issue.
I’ve incorporated 10 different layers and cross faded between them along side the Autopitch function. Still, it’s just not it, because of the formant shifting.

My question was more general -can Fmod pitch shift while retaining the formant in place?
It seems not, so do Fairlight have any plans to do so in the future? seems like a must have killer feature to me.


(リチャード清水) #4

Hi Hagai,

Unfortunately, the kind of real-time processing you propose is too expensive for most games audio resource budgets. Autopitch, while imperfect, provides a good balance of fidelity to the original engines without being too expensive.

The example events are industry standard techniques (used in games like Forza) for creating car engine sounds. If you feel the pitching is too extreme, you need to adjust the root pitch settings in each single module you’ve placed in the event. If you still feel the pitch shifting is too extreme, try bringing in more samples with even smaller auto-pitch settings.

It is possible to achieve formant shifting using FMOD, but would require you to create a custom DSP.

An alternative to this would be to use AudioGaming’s AudioMotors plugin (found in “Add Plug-In Sound” > “AudioGaming” > “AudioMotors”).


(Hagai Davidoff) #5

Thank you very much Richard for the informative reply.
I see your point!