Voiceless Fricatives in Northern Lisu Rael Stanley, Marija Tabain, David Bradley & Defen Yu La Trobe University Lisu is part of the Loloish branch of the Tibeto-Burman language family, spoken by roughly one million people in south-western China, northern Myanmar, Thailand, and Arunachal Pradesh (Bradley, 2003). The language is related to Lahu, Jingphaw, and Yi languages, and has several main dialects, broken into Northern, Central, and Southern. Northern Lisu – spoken in and around the Nujiang Lisu Autonomous Prefecture, in Western/Northwestern Yunnan Province, China – has a five-way contrast in place of articulation for fricatives, most of which have a two-way voicing contrast (the exception being /h̃/, which has no voiced counterpart) (Yu, 2003). The fricatives in this variety of Lisu are /f, v, s, z, ʃ, ʒ, x, ɣ, h̃/ - however, there is a restricted distribution among some of these fricatives (Yu, 2003). This study presents an acoustic phonetic examination of the voiceless fricatives in Northern Lisu /f, s, ʃ, x/, including the allophonic variation of /ʃ/ as either [ʃ] or [ɕ]. /f/ and /x/ are usually classified as non- sibilant fricatives, and /s, ʃ/ and [ɕ] are classified as sibilant fricatives (Ladefoged & Maddieson, 1996). Despite the IPA classification of [ʃ] as post-alveolar, and [ɕ] as alveo-palatal, recent work has suggested that the contrast is instead one of lip-rounding, rather than lingual place of articulation (Yoshinaga, Maekawa, & Iida, 2021), and for this reason we examine this contrast in relation to vowel context. Using wordlist recordings obtained from native speakers in their early 20s (N = 9, five male speakers and four female speakers), spectral data were extracted using the emuR package (Winkleman, Jaensch, Cassidy, & Harrington, 2018) interfaced with the R statistical package (R Development Core Team, 2008). Averaged FFT spectra are shown in Figure 1 below, separately for male and female speakers. A total of 990 tokens are included in these figures (648 for males, and 342 for females). An examination of FFT spectra shows that /x/ has similar spectral energy to /h̃/ for female speakers, but slightly higher for male speakers (though, still low energy above 2.5 kHz; and /f/ has more energy than /x/ but less energy than the coronal fricatives in this same frequency range. In line with data from many other languages, /s/ has a broad spectral peak in the range of 4-8 kHz. [ʃ] and [ɕ] both have a spectral peak in the frequency range of 2-4 kHz (slightly higher for females); however, [ʃ] has more energy than [ɕ] overall. This suggests that the lip-rounding of [ʃ] serves to boost spectral energy in this fricative compared to [ɕ]. If we assume the same place of lingual articulation for these two sounds, and if we similarly assume that airflow is being channelled towards the teeth as a secondary obstacle to the turbulent airflow which serves to increase the overall acoustic energy of the fricative (Shadle, 1985), then this result provides an insight into whether both of these sounds may be classified as sibilant or not. These results highlight the fact that detailed phonetic study of less well-documented languages can provide clarification for phonological theory.