An automatic speech recognition system for recognizing a user (2) voice command in noisy environment, comprising -matching means for matching elements retrieved from speech units forming said command with templates in a template library (44); characterized by -processing means (32, 36, 38) including a MultiLayer Perceptron (38) for computing posterior templates (P(O template(q) )) stored as said templates in said template library (44); -means for retrieving posterior vectors (P(O test(q) )) from said speech units, said posterior vectors being used as said elements. The present invention relates also to a method for recognizing a user voice command in noisy environments.