# Optimization issues while working with SteamAudio through FMOD

**URL:** <https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558>\
**Category:** Unity\
**Created:** [January 31, 2025, 12:57pm UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558 "2025-01-31T12:57:08Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![MarIva](https://avatars.discourse-cdn.com/v4/letter/m/9e8a1a/32.png) [@MarIva](https://qa.fmod.com/u/MarIva)\
**Post date:** [January 31, 2025, 12:57pm UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/1 "2025-01-31T12:57:08Z")

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Hi there!  
Is there any chance for occlusion to work WITHOUT transmission being checked? We’ve making a VR project on Android and met the optimization issuies while working with SteamAudio. The occlusion is noticeble only when transmission is checked. But without transmission there is a great growth of FPS.

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**Author:** ![Leah\_FMOD](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/leah_fmod/32/3685_2.png) [@Leah\_FMOD](https://qa.fmod.com/u/Leah_FMOD)\
**Post date:** [February 4, 2025, 6:00am UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/2 "2025-02-04T06:00:43Z")

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Hi,

Occlusion and transmission are two different settings, so clarify, what is the desired effect in your case? Occlusion determines how a sound is blocked by an obstacle, while transmission determines how a sound is affected after passing through an obstacle. A sound being occluded means that it will be completely inaudible, while transmission and attenuates/filters the sound that passes through based on the obstacle.

That said, the internal workings of how SteamAudio handles occlusion/transmission aren’t something that FMOD controls, and the use of raycasting in these calculations means that enabling them will incur additional CPU usage. You should be able to reduce this somewhat by decreasing the occlusion samples and max transmission surfaces for a Steam Audio Source component in engine.

If this isn’t enough, one workaround might be to disable “simulation-defined” occlusion/transmission in favor of “user-defined”, which may give you more flexibility in terms of the complexity of the calculation. However, you will also need to perform the raycasting calculations in Unity yourself, and provide the values to FMOD Studio via parameters that automate the relevant properties on the Steam Spatializer.

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**Author:** ![clemensamon](https://avatars.discourse-cdn.com/v4/letter/c/8baadc/32.png) [@clemensamon](https://qa.fmod.com/u/clemensamon)\
**Post date:** [February 5, 2025, 9:05am UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/3 "2025-02-05T09:05:36Z")

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Hi MarIva.  
May this example of using Unity with FMOD and atmoky spatializer help with optimizing your occlusion issue? [https://www.youtube.com/watch?v=a3xa52JjIPs](https://www.youtube.com/watch?v=a3xa52JjIPs)  
The demo scene including the raytracing method comes with the download of trueSpatial plugins for FMOD.

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<div class="post-metadata">

**Author:** ![MarIva](https://avatars.discourse-cdn.com/v4/letter/m/9e8a1a/32.png) [@MarIva](https://qa.fmod.com/u/MarIva)\
**Post date:** [February 6, 2025, 10:28am UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/4 "2025-02-06T10:28:47Z")

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Hi,

It was a revelation for me that the occluded sound becomes completely inaudible. Then I know that I can’t use it without transmission for my purposes.  
Speaking about optimization, I just reduced the quantity of occlusion samples and it helped a little.

Thanks a lot and have a nice day!

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<div class="post-metadata">

**Author:** ![MarIva](https://avatars.discourse-cdn.com/v4/letter/m/9e8a1a/32.png) [@MarIva](https://qa.fmod.com/u/MarIva)\
**Post date:** [February 6, 2025, 10:30am UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/5 "2025-02-06T10:30:08Z")

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Hi clemensamon,

Thank you for this video, I think it will help me with my future projects. For now I also want to save an HRTF model which SteamAudio provides.

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**Author:** ![Leah\_FMOD](https://yyz2.discourse-cdn.com/flex036/user_avatar/qa.fmod.com/leah_fmod/32/3685_2.png) [@Leah\_FMOD](https://qa.fmod.com/u/Leah_FMOD)\
**Post date:** [February 7, 2025, 2:31am UTC](https://qa.fmod.com/t/optimization-issues-while-working-with-steamaudio-through-fmod/22558/6 "2025-02-07T02:31:16Z")

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Happy to hear, feel free to let us know if you run into any more issues!