A number of Tamil nouns that end in à -du undergo gemination (parallel to the situation with nouns in ì du) to ¥à ttu. The geminated sequences are voiceless; the intervocalic non-geminate à du are of course voiced and flapped.
Native Dravidian words and borrowed English words like ØÀÔà roodu alike undergo this process. (Some Tamil speakers feel that English loans should not be subjected to this process, but naive speakers tend to do this anyway.)
Examples: ½Ôà paadu `lot, part' 
½Ô¥à paattu `(of the) lot, part'; ÂÖà
viidu 
ÂÖ¥à viittu `of the
house'; ´Ôà kaadu 
´Ô¥à
kaattu `of the forest, jungle'.