Well now I am not a coder ,so I will not be at all surprised if something passes me by.
My browser is FireFox.
It plays all sound files, that is except the one[if there is one] on the URL you have given - here I got-
the warning - 'FireFox cannot play sound files'
So I assume it relates only to that link.
But armed with the knowledge of that site why not dial up the FireFox Forum and pose it there?