This study investigated the effect of linguistic background on listeners’ perceptual judgement of hypernasality. Twenty -four listeners (12 Cantonese and 12 English) rated 9 non -nasal Cantonese sentences spoken by speakers with hypernasality due to different aetiologies, using direct magnitude estimation. Results showed that Cantonese listeners were significantly ( t = 2.125, p < 0.05) more reliable at judging hypernasality in male speakers than English listeners (Cantonese r = 0.55; English r = 0.39). Furthermore, Cantonese listeners gave a mean rating of 94.88 to male speakers, which was significantly higher than the ratings assigned by the English listeners (mean 79.16; t = 2.492, p < 0.05). Cantonese listeners also gave significantly higher ratings to the female speakers (mean 96.99) than did the English listeners (mean 67.36; t = 3.521, p < 0.05). However, both groups of listeners ranked the speech samples in a similar way. The results suggest that listeners who have minimal knowledge about the phonetics of a language may tend to be relatively conservative and thus possibly underestimate the degree of hypernasality present when making perceptual judgements of speech.