Noise reduction system and method of processing a noisy input signal and a noise signal to provide a reduced noise output signal, and respective cell phone

摘要

"SYSTEM FOR REDUCING NOISE AND METHOD OF PROCESSING A NOISE INPUT SIGNAL AND A NOISE SIGNAL TO PROVIDE A REDUCED NOISE OUTPUT SIGNAL AND THEIR CELL PHONE". Voice optimization is provided in dual microphone noise reduction systems by the inclusion of spectral subtraction algorithms using linear convolution, causal filtration and / or exponential mediation subordinated to the spectrum of the spectral subtraction gain function. According to typical embodiments, when a distal mouth microphone is used in conjunction with a proximal mouth microphone, it is possible to treat non-stationary background noise while the noise spectrum can be continuously estimated from a single block of input samples. . The distal mouth microphone, in addition to capturing background noise, also captures the user's voice, albeit at a lower level than the proximal mouth microphone. To optimize noise estimation, a spectral subtraction stage is used to suppress the voice in the distal microphone signal from the mouth. In order to optimize the noise estimation, a coarse voice estimation is formed with another stage of spectral subtraction from the proximal signal of the mouth. Finally, a third spectral subtraction function is used to optimize the proximal signal from the mouth by suppressing background noise using the optimized background noise estimation.