Date of Award

Spring 1-1-2017

Document Type


Degree Name

Master of Arts (MA)



First Advisor

Rebecca A. Scarborough

Second Advisor

Mans Hulden

Third Advisor

Barbara Fox


The Perceptual Assimilation Model (PAM) claimed that two types of non-native contrasts are easiest to discriminate: 1) when two sounds are assimilated into two different native categories; 2) when one sound is categorized while the other is not (Best, 1991). However, some study found the latter is worse discriminated than the former (Guion et al., 2000). The current study asks why such disagreement emerges and postulates that it is cause by PAM not allowing multiple-category assimilations.

30 Mandarin and English native speakers conducted three experiments: discriminating English contrasts /i/-/ɪ/; /eɪ/-/ɪ/; /ɛ/-/æ/; /ʊ/-/u/; assimilating those English vowels into Mandarin categories; and rating their goodness in the categories.

The results indicate that contrasts with no overlap in the native assimilation categories (/i/-/ɪ/, /ʊ/-/u/) are more discriminable than those with overlap (/eɪ/-/ɪ/, /ɛ/-/æ/). I convert PAM’s Uncategorized-Categorized contrasts into overlapped or non-overlapped contrasts, explaining the disagreements on the discrimination of “uncategorized” sounds.