The theory of sense – independence of separate sounds is based on a subjective interpretation of sound associations and has nothing to do with objective scientific data. However, the sound of a word, or more exactly the way words sound in combination, cannot fail to contribute something to the general effect of the message, particularly when the sound effect has been deliberately worked out.
This can easily be recognized when analyzing alliterative word combinations or the rhymes in certain stanzas or from more elaborate analysis of sound arrangement.
Onomatopoeia is a combination of speech sounds which alms at imitating sounds produced in nature (wind, sea, thunder, etc.) by things (machines or tools, etc.) by people (singing, laughter) and animals. There are two varieties of onomatopoeia: direct and indirect.
Direct onomatopoeia is contained in words that imitate natural sounds, as ding-dong, burr, bang, cuckoo.
Indirect onomatopoeia demands some mention of what makes the sound, as rustling of curtains in the following line An example is: And the silken, sad, uncertain rustling of each purple curtain» (E. A. Poe), where the repetition of the sound [s] actually produces the sound of the rustling of the curtain.
Alliteration is a phonetic stylistic device which aims at imparting a melodic effect to the utterance. The essence of this device lies in the repetition of similar sounds, in particular consonant sounds, in close succession, particularly at the beginning of successive words: « The possessive instinct never stands still (J. Galsworthy)
Rhyme is the repetition of identical or similar terminal sound combination of words
Identity and similarity of sound combinations may be relative. We distinguish between full rhymes and incomplete rhymes. The full rhyme presupposes identity of the vowel sound and the following consonant sounds in a stressed syllable, including the initial consonant of the second syllable.
Incomplete rhymes present a greater variety They can be divided into two main groups: vowel rhymes and consonant rhymes. In vowel-rhymes the vowels of the syllables in corresponding words are identical, but the consonants may be different as in flesh – fresh – press.