I am certain I've heard the vocals/song/voice before but it's eluding me entirely. I can't even be certain what the native language is, beyond feeling like it's one of the Norse family (or maybe Celtic, but I think not).

It's mouth music; I am pretty sure it's Gaelic; I have also heard it. I'll get back to you.

[edit] It's "Bòg A'Lochain." I thought it was something I owned; it is, although the version I know has a different time signature altogether. It's a strathspey.

[edit edit] Here's a version with a closer speed and rhythm to the sample.