Ja...

My grandfather was from Värmland -- which is west Sweden and not so north. It borders Norway and some people have suggested that Värmland is more Norwegian than Swedish. He used to do an intonation similar to the one described in this video. It involved sucking in air. He used it to indicate positive approval. It was kind of like a ja without the vocalization. But it was not the same as the sound made in the video by the Swedes who live in Umeå. I don't hear Grandpa's style of intonation so much in modern Swedish speakers but I have heard it in a few other older immigrant speakers. For all I know they could have all picked it up in Minnesota.