Erik Aamot doesn't mumble, but the wall of noise that he has to get through does the job of mumbling for him.
The tambourine is ideal here: it throws up a fog around the other instruments, and this Swedish band likes to play through fog, a shoegaze moan of guitar. The substance of the noise -- all those tiny shakes and jingles -- gives it the appearance of being insubstantial, but the noise is ongoing, and heavy, a wall that bears forward against the listener. Erik Aamot's voice comes through this wall singing about love in words that sometimes carry over the border of intensity from exclusive attachment into socially withdrawn. "You are my only inspiration," he sings, which is flattering but also pathetic. You have only one? His voice is mild, uninflected, but strong enough to make itself known over the guitars. He doesn't mumble, but the wall of noise that he has to get through does the job of mumbling for him. "Here," you might say, "is the instrumental equivalent of the emotions that try to silence him, his doubt and shyness, but, look, he feels so strongly that he finds the strength to overcome."