Nasal place assimilation and the perceptibility of place contrasts

Typological studies of place assimilation show that nasal consonants are more likely to assimilate in place than oral stops (Cho, 1990; Jun, 1995, 2004; Mohanan, 1993). Jun (1995, 2004) argues that this typological asymmetry derives from a difference in the perceptibility of the place contrasts in nasal consonants and in oral stops. Since the place contrasts in nasals are perceptually weaker than the place contrasts in oral stops, speakers are more willing to neutralize the former. However, the previous phonetic and psycholinguistic experiments do not provide unambiguous evidence for the weaker perceptibility of the place contrasts in nasal consonants (Hura et al., 1992; Mohr & Wang, 1968; Pols, 1983; Winters, 2002). To offer additional experimental findings bearing on this debate, this paper reports two similarity judgment experiments and two identification experiments in noise, which all show the lower perceptibility of the place contrasts in nasal consonants in coda. The results are compatible with- and thus can lend support to-Jun’s (1995, 2004) idea that the asymmetry in place assimilation may result from a difference in the perceptibility of place contrasts.