High Quality Content by WIKIPEDIA articles! The voiced retroflex plosive is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ?, and the equivalent X-SAMPA symbol is d`. The IPA symbol is a lowercase letter d with a rightward-pointing tail protruding from the lower right of the letter. Like all the retroflex consonants, the IPA symbol is formed by adding a rightward pointing hook extending from the bottom of the symbol used for the equivalent alveolar consonant, in this case the voiced alveolar plosive which has the symbol d. Compare d and ?. Many Indian languages, such as Hindi, have a two-way contrast between aspirated and plain [?].