Actress and singer Naomi Ackie credits dialect coaches Tangela Large, Bridgette Jackson and Denise Woods with helping her immerse herself in the voice of the one and only Whitney Houston for the biopic “Whitney Houston: I Wanna Dance with Somebody,” and says nailing down Houston’s speaking voice was the key to inhabiting the role — especially since Ackie is English.

From Houston’s early choir days to catching her big break in the presence of legendary producer Clive Davis, to the more tumultuous moments of her career like her deterioration due to drugs and her declining marriage to rapper Bobby Brown, director Kasi Lemmons, Ackie, co-stars Nafessa Williams and Stanley Tucci as well as many more helped craft the prism through which audiences will glimpse the music artist in the TriStar Pictures release, now playing in theaters.

On top of mimicking Houston’s singing and performing techniques, Ackie also had...