4.3 The perceptual assimilation model (PAM) was developed under the background of best and her colleagues (best 1994 and 1995, and best et al., 1988) and the results of this study. These studies try to study the corresponding relationship between local and non-local speech classification caused by perceptual pattern assimilation. There are two types of PAM concerns: (1) two unclassifiable (UU) and (2) unclassifiable (UC). In UU mode, the voices of non-native speakers are within the scope of any specific native type, and they can be used as the discrimination of unclassified voices in different ways. Harley, etc. The classified sounds of (2004) and (2005) are assimilated into mother tongues other than tonal language (French and English), which belong to UU mode respectively. In the study of their Mandarin tone perception, people who speak English or French are not as good as those who speak Mandarin and other people who speak tonal language. However, French and English are not completely insensitive to tonal contrast. For example, when French audience failed in the test of identifying and classifying common speech, they showed psychological and physical sensitivity to common speech (Harley et al., 2004). Similar results are also found in the performance of some English listeners in this study. Some of them are musicians, and they perform even better in English subjects than listeners whose mother tongue is Mandarin, although there is no difference in tone between their mother tongues. From the phonetic differences of fairness, the predicted PAM of UU assimilation model is significant, according to their expressive tone perception.