Comment 4 for bug 1572434

Did a bit more work on this, and it kinda needs better support in anoise for togglable play/pause and stop to better meet what keyboards expect to happen (such as AudioPlay is meant to toggle playback)

Have got 5 further commits on my fork here https://github.com/johndrinkwater/ambient-noise/commit/96991c35e47080a94a7d961434940e2d3ab46007