Audio test
Expected result:
- the hashes in each set should be the same
- the hashes should vary between the sets
- the "empty" hash should be 95476ffd46d1cd34fe8de83585c325df2b06019c852a5f6445200f57bc954a1b
- hitting the refresh button should not change the values
- reloading the page should change the values (depending on CanvasBlocker settings)