Pyen (Hpyin, Phen; ) is a Loloish language of Myanmar. It is spoken by about 700 people in two villages near Mong Yang, Shan State, Burma, just to the north of Kengtung.Person, Kirk R. 2007. A preliminary phonological sketch of Pyen, with comparison to Bisu. Canberra: Pacific Linguistics.
Pyen borrows more from Lahu and Shan, while Bisu borrows more from Northern Thai and Standard Thai. Pyen and Bisu are both mutually intelligible, since the two form a dialect chain along with Laomian and Laopin of China, and some Phunoi varieties of Laos (Person 2007). Pyen shares 36% lexical similarity with Hani, 32% with Lahu, and 31% with Lisu.
References
http://sealang.net/sala/archives/pdf8/person2007preliminary.pdf Shintani Tadahiko. 2009. The Pyen (or Phen) language: its classified lexicon. Fuchu (Tokyo-to): Research Institute for Languages and Cultures of Asia and Africa.