"Horsfield (2001) investigates the effects of postvocalic on the preceding vowels in New Zealand English; her investigation covers all of the New Zealand English vowels and is not specifically tailored to studying mergers and neutralizations, but rather the broader change that occurs across the vowels.She has suggested that further research involving minimal pairs like "telly" and "tally", "celery" and "salary" should be done before any firm conclusions are drawn.