Answer for my situation: https://www.scirra.com/forum/no-sound-on-ipad_p854247?#p854247
I think I am running into this issue on iOS 8.1.1 on an iPad mini and an iPad 4. The first time the website is loaded all the sounds play properly. If I refresh the page, no sounds play. When I change from wudiware.com/gg to http://www.wudiware.com/gg, it will work once, and then not again. I uploaded a few different versions with preloading an effect on/off, and played around with the loader layout. Each time the app would play sounds once and then never again from the same link. I tried closing the tabs. I tried forcing down the browsers. I tried hosting the website on a different server. I tried clearing the cache and app data in chrome. Same result. The sound work fine on multiple reloads using Chrome on Win7. C2 r188 on most trials, and the last stable release on one set of trials. The window is being touched plenty, still no sound.