It seems all participants in the study were recruited from within Hong Kong. I wonder if being speakers of tonal languages has any effect. I'd be interested in seeing if the study could be reproduced with speakers of non-tonal languages.
> The findings from these three experiments are in accordance with the hypothesis that speakers of tone language employ absolute pitch as a feature of speech and that they refer to precise and stable absolute pitch templates in enunciating words.
> The present study does not address the question of whether absolute pitch, when acquired as a feature of speech, later generalizes to music.