21. A back vowel would be the / u / or " oooooooo " sound. 22. Stop consonants have palatal allophones before front vowels and velar allophones before back vowels . 23. Between back vowels , it may be silent or sound like a bilabial glide. 24. The technique is used by ventriloquists to mask the visible rounding of back vowels like. 25. Such stems break vowel harmony by combining front and back vowels : e . g. 26. The standard pronunciation is something between and, i . e . mid back vowel . 27. This developed historically from a prenasalized stop before a relatively high back vowel , such as. 28. Unrounded back vowels are typically centralized, that is, near-back in their articulation. 29. The short back vowel is higher than its long and nasal counterparts ( vs . ). 30. In Old English and Old Frisian, the back vowels were fronted to in certain cases.
