The title says it all 
Is there any current workaround for autoplaying audio on mobile browsers? Thx.
Since mobile browsers ignore the autoplay attribute on video and audio elements, I think the only option is to have the user click somewhere on your lp first - which is not really a workaround - so perhaps you should have code simulate this (user interaction) event. 
Just to be clear here - you want to autoplay audio on mobile browsers, rather than wanting to NOT autoplay audio on mobile but only on Web?
If you're looking to autoplay audio on mobile, my best understanding at the moment is that it's somewhere between "extremely tricky" and "not possible". You're essentially fighting the OS to do it, and all the tricks which used to work tend to get disabled as the OS upgrades. I've heard of one guy doing it by creating a shell app for iOS, but that sounds hacky and extremely unreliable to me.
This may be worth a read: http://stackoverflow.com/questions/1...-mobile-safari .
Of course it's an entirely different set of problems for Android. setMediaPlaybackRequiresUserGesture() is the way to get it working in apps using Webview, but that doesn't work in Chrome.
Overall: very tricky, fascinating problem, probably not practical to find a solution in a cost-efficient timeframe.