Extremely loud screeching error - Unity Plugin

[8ude]

I was working on an example project when I encountered this catastrophic, screeching feedback/buffer issue. I have no idea what is causing it - in the last few minutes of this video I go through all of the steam audio components in the scene, as well as the mixer routing.

Unity version 2020.3.20f1 Steam Audio version 4.0.2 Computer Operating system: Windows 10 Audio Device: RME Babyface ProFS

WARNING - TURN VOLUME WAY WAY DOWN BEFORE VIEWING VIDEO https://drive.google.com/file/d/1rlA7KPOXfTtnjmzlILSPupzCw5N33SRj/view?usp=sharing

I'm cautiously attempting to reproduce, but am not yet able to isolate the cause. It seems to happen at random, but may have something to do with the reverb. Baked reverb is more volatile than realtime.

Here's the Unity project if someone wants to look at it.

https://drive.google.com/file/d/1X5W3ExtVvS_wShC918G1ta8wUXGrVbEA/view?usp=sharing

[Oldnice]

Have had a similar issue myself. Happened in the latest Unreal Engine plugin (Steam Audio 2.0-beta.17), and in a custom integration with the latest SteamAudio (4.0.3).

For me, it has to do with transmission. If a sound is fully occluded, and material transmission is used for a simulation, sometimes the transmission parameters from the direct simulation results are way too high, and exaggerate the transmitted sound into a screeching horror. Manually limiting the simulation result transmission parameters to a sane value limit the issue, and disabling transmission removes the issue.

I'm not sure if I've configured the transmissive materials wrong, or if there's a bug in Phonon.

Here's a screenshot of the simulation results, which to me, seem to indicate a too high middle frequency multiplier:

[lakulish]

@8ude I was unable to reproduce the issue in the Unity project you shared. Maybe I just need to move the listener to the correct position to trigger it, do you have a specific point where the issue can be reproduced? Also, I noticed in the video that the pathing probe batch is not set, but it is set in the Unity project you shared, so that may have been the cause.

@Oldnice Could you provide a minimal Unreal project that reproduces the issue? Also, your screenshot seems to be from Steam Audio 2.x, do you have a repro case with screenshot in the latest release of Steam Audio? Thanks!

[Oldnice]

Hey @lakulish,

I have not had this issue in a few months. I've either managed to fix whatever was causing the issue, it's been fixed by a subsequent SteamAudio release, or it requires a very specific turn of events to occur.