The concept of sound change: sound change is the change of voice. When people speak, they do not send out one by one in isolation syllable (word), but to form a series of syllables into a natural "flow of speech".
assimilation
Two adjacent different sounds in a speech stream, one of which is affected by the other and becomes the same or similar to it in one or more characteristics. This change in speech stream is called assimilation 。 As in English, plural Suffix S should have been read as [s], but in dogs, because of the previous Dullness The influence of the pronunciation of g becomes voiced [z]. According to the direction of assimilation, assimilation can be divided into Cis assimilation Assimilation with reverse: Sequential assimilation refers to the assimilation of two adjacent sounds, the latter being affected by the former and becoming the same or similar to the former, such as in dogs and legs Clear consonant It becomes [z] similar to voiced [g]. Reverse assimilation of two adjacent sounds. The former is affected by the latter and becomes the same or similar to the latter, which is called reverse assimilation. For example, the phoneme n in Chinese [mianp'au] (cotton padded robe) is affected by the latter Bilabial sound The effect of [m] is. In English be in poor health, because of the influence of the next sound p, in will be pronounced as [m], which is also reverse assimilation. alienation
Alienation refers to two sounds that are originally the same or similar, one of which becomes different from its original pronunciation for some reason. If two Shangsheng characters in Putonghua are connected together, the first one cannot be pronounced Shangsheng, but must be read as similar to the rising tone This is the case with "cold water" and "elections". Another example is the first consonant in [nanny] in Chinese Rhyme tail The initial consonant of the last syllable is the same, but when connected, the final [n] is alienated to the rear nasal consonant [N]. weaken
In speech flow, some sounds may become weaker and lighter than before. This phenomenon is called weaken 。 For example, many of the neutral tones in Mandarin are typical of tone weakening, such as "one" in "look" and "de" in "my book". In addition, the vowels in the neutral syllables will change. The common performance is to move closer to [«]. If it is a compound vowel, it will become simple finals For example, "brother" and "steamed bun" can be read as [kFg «] and [mant'o] respectively, which is typical. There is also weakening in English and other languages, for example, the weak form of of [f] is pronounced as [« v], but [b à t] is pronounced as [b « t], etc. fall off
Some of the sounds in the speech stream are no longer pronounced or disappear due to concatenation and other reasons, which is called falling off, also known as Attenuation 。 as mandarin In Chinese, "we" can be read as [uom], "tofu" as [touf], and "children" as [þ iauxar]. In English, some auxiliary verb or Copula When linked with the subject, some phonemes will also fall off, such as I am → I'm, you had better Do → you'd better do, etc. 
