If there's a better solution I'd love to hear it, since this wouldn't work on iOS devices afaik.
http://caniuse.com/#search=web%20audio
If you want a nice abstraction library, check out howler http://goldfirestudios.com/blog/104/howler.js-Modern-Web-Aud...
as for IE support, well, there's not really that much risk in using soundmanager/flash if you still need to support 7 and 8, is there? I even discovered that old MS even exposed some nice windows media activex controls that you can use to do simple sound playing stuff without loading up a flash plugin, if you're that serious about backwards compatibility.
Forget a year from now. You can start using this stuff today, and by the time you release a year from now, things will be even better.