Recently I was trying to explain that I had (mis?)interpreted a Portuguese way of writing laughter, "kkkkkk", as the kind of sound Ernie from Sesame Street makes when he laughs. Here's a video with some examples. (I've been told this is not the general understanding of "kkkkk" among Portuguese speakers. But I have heard people in real life laugh like this.)
I had been hoping to explain it in terms of phonetics, partly because in my head it "made sense" for that sound to be related to the consonant [k], and partly because I had forgotten about the Ernie example. It seems to me like some kind of a voiceless fricative, made near the back of the throat. To make it myself, my lips are in a similar position as they are for [i]. But searching around Wikipedia's pages on various consonantal sounds made near where [k] is, like [x χ], I wasn't able to find anything that sounded quite like it to me.
Is there a phonetic classification for this kind of laughter? Or is this just not a sound used in any human languages?