Patent ID: 8918319
Filing Date: 2014-12-23
Classification: G10L

Abstract:
1. A speech recognition device, which receives and recognizes at least one key phrase containing at least one key word, comprising a sound pick-up array receiving a sound source signal of said key word to generate a plurality of audio signals; a frequency-domain converter connecting with said sound pick-up array to receive said audio signals and transforming said audio signals into a plurality of frequency signals; a spatial feature spotting device connecting with said frequency-domain converter to receive said frequency signals and obtaining a space-frequency spectrum and an angular estimation value therefrom; a spatial evaluator connecting with said spatial feature spotting device to receive said space-frequency spectrum and defining and outputting at least one spatial eigenparameter; a speech feature spotting and evaluation device connecting with said spatial feature spotting device and said frequency-domain converter to receive said angular estimation value and said frequency signals for performing spotting and evaluation and outputting a Bhattacharyya distance; and a detection device connecting with said spatial evaluator and said speech feature spotting and evaluation device to receive said spatial eigenparameter and said Bhattacharyya distance, having thresholds corresponding to said spatial eigenparameter and said Bhattacharyya distance preset, and using said spatial eigenparameter, said Bhattacharyya distance and said thresholds to determine whether said key phrase is correct; wherein said sound pick-up array is in form of an annular arrangement on an identical plane, and wherein said annular arrangement has a central point, and wherein distance between said central point and a circumference of said annular arrangement is R, and wherein said central point is used as an origin of a Cartesian coordinate system having a latitudinal axis X, a longitudinal axis Y and a vertical axis Z, and wherein a sound source point of said sound source signal, said central point and said plane form a triangular plane vertical to said plane, and wherein an angle φ is contained between a base of said triangular plane and said latitudinal axis X, and wherein an angle θ is contained between a hypotenuse of said triangular plane and said vertical axis Z, and wherein said space-frequency spectrum is expressed by  and wherein f=1 . . . F, and wherein F denotes FFT size, and wherein ω  and wherein c denotes light speed, and M is a number of receivers of said sound pick-up array, and wherein  and wherein V(ω  and wherein λ wherein said spatial evaluator simultaneously receives said space-frequency spectrum and said angular estimation value to define and output two said spatial eigenparameters; and wherein said spatial eigenparameter defined by said space-frequency spectrum is an angular estimation quantity  and wherein D is a normalization factor and F′ a formant frequency band, and wherein said spatial eigenparameter defined by said angular estimation value is an angular estimation variance x