Guten Abend Huw,
the two things are indeed not too bad and I hadn't mentioned them if you hadn't asked to tell you problems.
Maybe what I hear is not hissing (not sure about the correct English word) it could be breathing, maybe Catrin is too near at the micro, but I hear it only in this section (where "ges i amser da" is introduced) When Aran introduces "a glass or two" the sound is again perfect.
But it is not bad at all, I can easily understand what Catrin say.
Es tut mir leid, wenn ich dir unnötige Arbeit verursacht habe.