Changes in the phonological system mainly affect consonant clusters that show sandhi processes. Phonologically, Hokkien is a tonal language with extensive tone sandhi rules. Voiced stops may have been the result of rules of allophony, elision, or sandhi. However, morphemes retain their spelling despite sandhi. These changes are subject to sandhi in Sanskrit. Yaghan shows a number of sandhi effects on consonants and vowels. A related phenomenon is the final consonant sandhi. All but the Hainan dialects have complex tone sandhi systems. Taiwanese Tone Group Parser is a simulator of Taiwanese tone sandhi acquisition. These dialects are also noted for extremely complex tone sandhi systems. These affixes function by a rule of internal sandhi. As with sandhi in other Min Nan dialects, the checked tones interchange. Pronunciation also varies with context according to the rules of tone sandhi. In connected speech, an open rime shifts to its close counterpart in the tonal sandhi. Technically, it is a type of external sandhi, which is disrupted in pausa.