Noisiest day - leaving Sarria it quickly became evident that some Spanish women were convinced they had the most beautiful singing voices in the world, and were determined that you should know that even if you were several hundred metres away.
Noisiest night - staying in the Xunta albergue at Ribadiso. It isn't (or wasn't) locked up, and pilgrims could come and go as they pleased during the night. Some took advantage of this to return in the early hours of the morning, rather inebriated, and making enough noise to wake up many people in the dormitory.
I was allocated a bed near the door out to the toilet blocks, and enjoyed the steady stream of revellers needing to relieve themselves. Most merely needed to empty their bladders, but inevitably, one needed to empty his stomach. At some point I got out of bed and closed the door he had left open in his haste to talk to the porcelain pony, which muted some of his conversation.