is  an umbrella term used to describe a number of definitions. For example, noise, in a derogatory fashion may imply the production of sound, of music or singing is unwanted and simply seen as a disturbance of the otherwise peaceful environment.
In linguistics, an allomorph is a variant form of a morpheme, that is, when a unit of meaning varies in sound without changing meaning. The term allomorph explains the comprehension of phonological variations for specific morphemes.
1 If the word following the indefinite article begins with a consonant, the allomorph a is selected, but if it begins with a vowel the allomorph an is used instead. . ... [ 2 A]llomorphs of a morpheme are in complementary distribution. 3  This means that they cannot substitute for each other.