Looking to implement a "Talking while mouth is full" effect

Hello. Unity Developer here. I am working on a multiplayer game that uses voice chat with FMOD. I’m planning on implementing a game mechanic that will force the player to have something in their mouth. They will still be able to speak but I’d like their voice to sound as if they are talking with their mouth full. I was wondering if anyone had any ideas as to how I would approximate such an effect/filter using FMOD Studio…

If your voice chat is already routing through an fmod bus/group, I would consider just setting a parameter for that “mouth is full state”. The next step from there is just getting the desired effect.

You could use a simple low pass filter to muffle the sound when that parameter is at the value you set. That would be done through automation. If you want to just see an overview of how that works, this is a nice video!

https://youtu.be/xC8ssCCiRUQ?si=QS2U-GS2P4TLI08D

What @JSMallard has suggested would be a good starting point for an approach that solely uses the effects available in FMOD Studio. I would also recommend playing around the multiband dynamics effect in 2.03 to limit the high end to remove aspirants/transients, and compressing the mid/low end with some makeup gain to reduce the dynamic range but maintain a similar peak.

As for a non-effects based approach, depending on what you want to accomplish, you may wish to experiment with having prerecorded mouth-full audio, and then dynamically mix between the voice chat audio - for example, using a sidechain from the voice chat audio to control the gain or expansion of mouth-full audio.