Google takes a decidedly more puritanical view towards “naughty” voice searches than it does toward comparable typed searches.By default, Google blocks voice search results that it deems offensive. Presumably, its motive has less to do with keeping you from cussin’ than with shieldingA users from questionable content in the event that Google’s software misunderstands their spoken request for “pictures of shih tzus,” “chicken plucking contest,” or “How can I get to Bangkok?” What could possibly go wrong, you ask? Just think of Google voice search as a spoken-word equivalent of autocorrect.
http://www.techhive.com/article/2091416/these-are-the-filthy-words-google-voice-search-doesnt-want-to-hear.html
http://www.cio.com/article/747303/These_Are_the_Filthy_Words_Google_Voice_Search_Doesn_t_Want_to_Hear