A phonestheme is a sound, sound cluster, or sound type that is directly associated with a meaning. The shared cultural response to a phonestheme is called phonesthesia , and the study of phonesthemes and phonesthesia is called phonesthetics . Secondary sound symbolism Secondary sound symbolism is the study of minor aspects of sound symbolism including ablaut modification, reduplication, spoonerisms, rhyming slang, malapropisms, and folk etymology. Ablaut modification is the process whereby new words are formed by the modification of the vowel of an already existing word. For examples of ablaut modification , see the end of my Dictionary of English Phonesthemes.
Reduplication is the use of a repeated sound segment in a lexeme.
In English, reduplication plays only a small role in word formation. I think, in English, reduplication signals silliness, triviality, or informality. Blending is the process whereby the sounds of two or more words are combined to form a new word. Blending is obviously very closely related to phonesthetics. A spoonerism is an erroneous or humorous transposition of two or more sounds in a word or phrase.