Static-like noise on IOS

Development Audio
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21

Hi.

I’m updating this topic with new info, because the problem still persists with numerous assets for no obvious reasons. Below is a comment from our sound designer:

Recently I found a major issues with sound in Unreal Engine 4.

When we build a game for iOS something strange is happening with stereo files. For sampling frequency different than 44.1kHz right channel is playback with wrong speed and pitch. For 22.05kHz - right channel is playback to fast, for 48kHz is playback to slow. Please find a recorded audio files attached.

Other thing is very low sound quality. even when compression quality is high a lot of drops and pops appears. Please find a recorded audio files and print screen from Pro Tools attached.

I try to fix this issues but with no luck. What I tried was:

  • adding short silence at the beginning and end of sound asset
  • various sampling frequency, 44.1kHz, 48kHz, 22.05kHz
  • send all sounds only to default Master Bus
  • various compression quality 1 to 100
    More info:
  • drops and pops appears often just after some sounds
  • making new build with the same setup can change drops and pops

So far we tried replicating the issue with template project and the same assets, but with no luck. So the same assets will cause problems in one project, but not the other.

Link to with sounds and screens mentioned above: https://www…com/sh/2099yzrxq1bnqg7/AADiBk_7k8DcgqAd7hCd6UWGa?dl=0

Any help or idea how to pinpoint the problems would be appreciated.

22

Hey ,

So I have added your sound files to a project and pushed the project to both an Android device as well as an iOS device. Both devices played the sound exactly the same.

With that being said, I’ve requested some additional feedback from our Developers regarding the frequency for mobile devices. I’m hoping to hear some more information within the next couple of days.

Please let me know if you have any further questions, thanks!

23

Hey there, I just solved this issue today on 4.9.2.

It seemed to be the compression quality setting for each sound file. The “Recommended” sound compression of 40 caused a constant static hiss during the audio play. Turning this instead to 100, thus pretty much turning off audio compression, seems to fix it. I’m not sure if iOS is doing it’s own compression on top of the unreal compression, but it worked for me!