How to: SFX for a game that can speed up?

How would one go about implementing SFX for a game that can speed up?
The game is a tower defence game.

If the game is at 1x speed and can be triggered to go to 2x speed, 4x or even 8x speed, some SFX that have longer release times arn’t going to match up well with certain things at such high speeds…

Without having to re-make a faster sound for all of these sounds at different speeds, is there a way to tackle the problem without sound varying in pitch and/or artifacts that pop up during speed dialation of SFX when mulitpler speeds are triggered?

Using Unity, Windows, latest fmod and Cubase FYI.

It’s pretty tricky, and I’d love to hear how people have approached this problem.
I guess it’s impossible to make even a 2x speed change in realtime without audible artifacts, so 4x or 8x… If it’s just a release tail problem, maybe stopping those events earlier, with a set release time, or even better: an automated release time, could be enough for some sounds?

There’s about three options I can think of for a situation like this:

  1. Use the event/bus pitch macro in conjunction with the FMOD Pitch Shifter effect. Raise the event/bus pitch macro to increase the speed of the event and the pitch shifter to bring the actual pitch back down to normal levels. This method requires some tweaking of the Pitch Shifter effect to reduce artefacts but will never completely remove them.

  2. Create separate sound effect assets that play when the game is playing at 2x+ speed. You’ve mentioned you want to avoid doing this, but this method will guarantee quality of the sound effects if you need them to sound a certain way.

  3. You can break your existing sound effect assets down into individual “chunks”. Each asset is an individual instrument in the event, and either they are placed on a parameter sheet that moves at the same pace as time, or they are placed in your game’s animation sequencer. Either way, this is to achieve getting the instruments (“chunks”) to trigger faster without compromising pitch. Take a look at the Celeste FMOD project’s side B music for an idea of what I’m talking about.

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