Patent ID: 8744846
Filing Date: 2014-06-03
Classification: G10L

Abstract:
1. A noise state determination method of a noisy speech signal, the method comprising: calculating a transformed spectrum by transforming an input noisy speech signal to a frequency domain; calculating a smoothed magnitude spectrum by reducing magnitude differences of the transformed spectrum between neighboring frames; calculating a search spectrum which represents an estimated noise component of the smoothed magnitude spectrum; and calculating an identification ratio which represents a ratio of a noise component included in the input noisy speech signal, by using the smoothed magnitude spectrum and the search spectrum; wherein a whole frequency range of the frequency domain is divided into subbands, and the calculating of the search spectrum and the calculating of the identification ratio are performed on a sub-band basis, and wherein the search spectrum is calculated by using Equation E-1 wherein, i is a frame index, j (0≦j<J<L) is a sub-band index obtained by dividing a predetermined frequency range 2