I'm so glad I found this thread. yCUzWzM2HJGV IJCT just to be sure have you guys physically published to the App Store or is this a browser based app? Did you use Intel XDK or other wrapper?
I'm experiencing this exact problem on an app published on 27th August to the iOS App Store. When you press the home button to come out of the app, and then go back into it, every single SFX that has played so far IN THAT LAYOUT will play at once. This could blow the speakers on the device! It affects all SFX that have been placed inside the "Sounds" folder. The bug has been seen on iPad Air 2 and iPhone 5c (devices we have available) both of which have the latest version iOS installed.
The app is exported out of Construct with the Cordova option and then we use Intel XDK to wrap as an iOS app. Also created a test app and was able to reproduce them all playing when coming back into the app. It seems the issue is in the export process of either Construct or XDK, as it won't happen when previewing.
Made quite a long worded thread about this in the General forum, but no replies. Have since done some tests so I'm going to make another thread in here very soon with better information.
This is quite a big issue and we're also experiencing some even worse audio problems that could be related. We get a random loud POP or BZZT that often kills all audio on the app permanently, EVEN IF THE APP IS RESTARTED. Only fixes itself if another app with sound is loaded before loading the my app again. That issue can sometimes trigger when receiving a touch input. Might have something to do with music only being able to be heard after a touch input?
Another issue we have is all SFX randomly becoming very low quality, sounding bitcrushed and lower pitch.
So weird and frustrating! We've staggered an update to our app just because of this issue and have lost WEEKS OF TIME OVER IT. This needs to be addressed ASAP.