Māori is the only indigenous language of Aotearoa/New Zealand. It is southern most Polynesian language, spoken by some 160,000 (~4% of population. Māori is an endangered language despite significant efforts to revitalize the language since the 1980s. The MAONZE (Māori-New Zealand) project team have been studying Māori sound change over time, focussing on vowels and rhythm, attempting to determine both internally and externally motivated change. Data includes three groups of male and female speakers, historical speakers born in the 1880s, present day elders born between 1920 and 1944, and young speakers born between 1969 and 1985. The pronunciation of vowels in Māori was changed over time. For example, /u u:/ have become more “fronted” and /e e:/ have become more “raised” Evidence for diphthong mergers between /ai/ and /ae/ and between /au/ and /ou/. There has been a loss of durational distinctions between long and short vowel pairs. There is a significant difference in the vowels of the present day youth compared to both the present day and historical elders.