Tsum, or Tsumge (ttz), is the language spken in the Tsum valley, an area almost completely surrounded by 6500m peaks, with the valley opening to the south-west, and a pass to Tibet in the north.
Phonological analysis is preliminary, but is seems that a variant of Huber's Kyirong Tibetan analysis will accommodate the Tsum data. The only major changes are: the addition of a voiceless rhotic, a general retroflex approximant articulation for the rhotics, the voiceless lateral not having a fricative articulation, and the presence of a rising tone.
Recordings of Tsum words and phrases can be found here.
More information about Tsum can be found on the homepage of the Tsum valley Welfare Organisation.
Tsum valley view.