Besides some riotous birdsong early in the morning, and the lowing of cows in Galicia, the sounds I mainly recall were those of blissful silence. I used to wonder at those pilgrims who seemed to be trading that silence for whatever sounds were coming out of their ear phones. The only exception to this was the time we were passed by a very outgoing peregrina whom we had met earlier when she passed us, plugged in, singing along at the top of her lungs, a song from the opera Carmen. (She had a very good voice.)
Oh, yes, and there was the time we were walking along a narrow path between an open field and a hedgerow when we could hear the bleating of sheep, along with their sheep bells. The hedgerow was so thick, we couldn't see through, but the sheep were certainly, mere feet away.
And there was that morning entering a little village in Galicia when we heard a woman's voice calling very loudly several times, I think it was, "Vacas, vacas," then shortly after having to scamper out of the way as she opened a barn door and her cows went careening towards a fresh dew-covered pasture.