Abstract:
Sound change over time has been identified in monophthongs in Māori, the language of the indigenous people of NZ [1], with /u u:/ fronting, the mid vowels rising, so that /i~i:~e~e:/ can appear identical, and the quantitative distinctions between long and short monophthongs being reduced apart from /a~a:/ [1], [2]. The five most frequent diphthongs in Māori are /ai ae au ou ao/. Analysis has shown mergers between two pairs of these diphthongs, /ai~ae/ and /au~ou/ [3]. This study argued that only one of these mergers is due to the monophthong movements: we have shown that /e e:/ have risen [3], but the second target of /ae/ is falling. It was suggested that this merger is due to glide weakening of /ai/. The merger of /au/ and /ou/ is probably influenced by the fronting of /u u:/. The major distinction for /au ou/ is in the first target, but the fronting of T1 for both /au/ and /ou/ is highly correlated both to the fronting of T2, and the fronting of /u u:/ [3]. Diphthong analysis to date has only offered schematic formant trajectories with arrows from T1 to T2 indicating the movement [2], [3]. Here we present for the first time an analysis of the vowel mergers looking at the entire diphthong trajectories, for T1 and T2 for the male speakers. These plots reveal the course and timing of the diphthong movements.