Theories of Syllable Formation and Syllable Division
There exist different theories expressing different points of view on syllable formation and syllable division.
1) The most ancient theory states that there are as many syllable as there are vowels in a word. The theory is primitive and insufficient because it doesn't take into consideration the consonants which in some languages can be syllabic and moreover the theory doesn't explain the boundaries between syllables.
2) Among the oldest theories is the so-called expiratory theory (chest-pulse). According to this theory the syllable is a sound or a group of sounds that are pronounced in one chest-pulse. There are as many syllables in a word as there are chest-pulses made during the utterance of the word. Each vowel sound is pronounced with increased expiration that's why vowel are always syllabic. Boundaries between syllables occur in the places where there are changes in the air pressure. The theory doesn't explain all the cases of syllable division, e.g. it is doubtful that juxtaposed vowels are pronounced with a double chest-pulse, though linguistically they are divided into 2 units. In the pronunciation of the word 'star' there are 2 expiratory pulses (in the pronunciation of 's', 2 – pronunciation of 'tar'), and yet the word is mono-syllabic.
3) sonorative theory. It was devised by Otto Jesperson. According to this theory there are as many syllables in a word as there are peaks of sonority. Sonority means prominence, audibility of sounds. Pronounced with uniform force, length and speech speech sounds differ in sonority. Jesperson established a scale of sonority of speech sounds. According to the scale open vowels are the most sonorous. Then come other types of vowels, then sonants (r,l,m, etc), voiced consonants, voiceless consonants, and voiceless stops (p,t,k) are the least sonorous sounds. There are 8 levels of sonority. E.g. sudden
/sʌdn/ Sounds are grouped around the most sonorous ones which form the peaks of sonority. One peak of sonority is separated from another one by sounds of lower sonority. Two points of lower sonority constitue the beginning and the ending of a syllable. There are some cases contradicting Jesperson's theory, e.g. star, next, skate
/stɑ:/. The sonorative theory doesn't explain the mechanism of syllable formation. It attemps at explaining our perception of syllables without explaining rules of syllable division. E.g. /əneɪm/. Jesperson realized that the theory is not universal.
4) Muscular tension theory or the articulatory effort theory. The theory was devised by Lev Sherba. He suggested only the idea and it was later worked out by Sherba's disciples and followers Matusevich and Tarsuev. A syllable is characterized by variations in muscular tension. It increases at the beginning of a syllable, reaches it maximum with a vowel or a sonant and decreases towards the end of the syllable. A syllable is an arc of muscular tension. The boundaries between syllables are determined by the occurrence of the lowest articulatory energy.
/pɑ:t/Accroding to the theory there are as many syllables in a word as there are maxima of muscular tension.
/mɪs|teɪk/. Consonants within a syllable are characterized by different distribution of muscular tension. In accordance with this there can be 3 types of consonants: 1) initially strong consonants or finally weak. They are the consonants in the articulation of which the beginning is stronger than the end. These consonants occur at the end of a closed syllable; 2) initially weak consonants or finally strong. In their articulation the beginning is weaker than the end. They occur at the beginning of a covered syllable; 3) double-peaked consonants. In their articulation both the beginning and the end are energetic while the middle is weak. Acoustically such consonants produce an impression of 2 consonants. They occur at the junction of words or morphemes and the syllabic boundary is within them. E.g. penknife.
/ən|eɪm/ /ə|neɪm/ /ɑɪ sɔ:|hə:|r|ɑɪz/ (| or |depending on whether /r/ is initially weak or strong)
5) The loudness theory. Worked out by Nikoly Jnkin. Unlike the previous theories takes into consideration both the production and perception levels of syllables. Jinkin found out experimentally that the organ responsible for the varation of loudness in the syllable is the pharynx. Perceptually the peak is louder and higher in pitch than the slopes of the syllable and on the perception level the syllable is defined as an arc of actual loudness. On the speech production level the arc of loudness corresponds to the arc of muscular tension.
The theories of syllable are correct but to a certain extent and none of them can reliably explain all the cases of syllable boundaries.