The Nuosu (Nosu) Yi language, or Northern Yi (北部彝语), is spoken by approximately two million people in southern Sichuan Province and northern Yunnan Province, China, the majority of whom are monolingual. Yi is a member of the Yi Branch of the Lolo-Burmese subgroup of the Tibeto-Burman family (Benedict 1972/2009, Bradley 1979), which includes some 50 languages, also called the Nisoic languages (Lama 2012) or Ngwi Group. The large (5 million) ethnic Yi nationality groups of Yunnan Province are distantly related. The third author, Lama Ziwo, who was 31 at the time of recording, produced, translated and transcribed the recorded audio data phonemically and participated in the laryngoscopic filming of the video data. He is a native speaker of the Suondip/Suondi dialect, and a fluent speaker of the Shypnra/Shengza dialect. It is the Shypnra/Shengza standard dialect that is being represented in this paper. The most distinguishing phonetic feature of Northern Yi is its systematic vocal register contrast (Matisoff 1972, Dai 1990) between two settings of the laryngeal constrictor mechanism, which are referred to as a lax (unconstricted) series and a tense (constricted) series (Edmondson et al. 2000, 2001). The contrast is realized as a distinction in resonance (spectral quality) rather than as contrasting phonation types as in some other forms of Yi or in other Tibeto-Burman languages (e.g. Bai). The consonantal inventory is large, with complex vocalic interactions, including interactions with two pairs of fricativized vowels. Northern Yi has 43 initial consonants, five pairs of vowels (or syllable rhymes), and three tones: 55, 33, and 21. Relevant reports on voice quality in related languages can be found in Maddieson & Ladefoged (1985) and Sun & Liu (1986).