Shortening of long vowels in unstressed syllables occurs irregularly. Syllables using long vowels are always stressed. The second syllable is thus still lower in pitch than both of the adjacent syllables. Characters for combined consonant and vowel syllables then follow. No short vowels appear in open stressed syllables. That caused a steady erosion of vowels in unstressed syllables. Russian has vowel reduction in unstressed syllables. The fundamental principles of an abugida apply to words made up of consonant-vowel (CV) syllables. Indonesian has four diphthong phonemes only in open syllables. This is more consistent with the syllabic consonant description of these syllables. Each loudspeaker produces a phrase consisting of two words or syllables. The number and placement of the unstressed syllables is rather flexible. In final unstressed syllables, results were somewhat complex. In Polish literature, couplets of Polish alexandrines (syllabic lines of 7+6 syllables) prevail. Alliteration essentially involves matching the left edges of stressed syllables.