Takes time, make sure you went through the setup routine. If you have the fan on make sure its not on high or on defrost. Mine is really hit or miss on voice recognition. Some days it's spot on other time I use some pretty choice words have the 7th or 8th misrecognition.
2011 JKU Sahara; Sahara Tan, Leather, 3.73, Auto, Hard/Soft Top, SpiderWebShade, Dead Pedal, Skid Row Foot Pegs, BFG KO2, 10a Wheels