15. A data storage device for storing data to be read by a computer system including program instructions for operating a speech recognition system, comprising: (a) program instructions for receiving voice input at a speech recognition engine; (b) program instructions for receiving an acoustic model at the speech recognition engine; (c) program instructions for defining a layered grammar and dictionary library to the speech recognition engine, the layered grammar and dictionary library defined before receipt of the voice input at the speech recognition engine, the layered grammar and dictionary library including, (i) a language and non-grammar layer that supplies types of rules a grammar definition layer can use and defines non-grammar the speech recognition system should ignore, (ii) a dictionary layer that defines phonetic transcriptions for word groups the speech recognition system is to recognize, (iii) a grammar definition layer that applies rules from the language and non-grammar layer to define combinations of word groups the speech recognition system is to recognize; and (d) program instructions for using the acoustic model and the layered grammar and dictionary library to process the voice input.
17. A data storage device for storing data to be read by a computer system including program instructions for operating a speech recognition system as recited in claim 15 , wherein the word groups of the dictionary layer are defined in accordance with a generic group listing or a grammar related group.