13. The non-transitory computer-readable recording medium of claim 11 , wherein the determining whether said voice frame is from a voiced sound, an unvoiced sound, or background noise comprises using neural network.
11. The non-transitory computer-readable recording medium of claim 10 , wherein the extracting a voice frame corresponding to a voiced sound among the plurality of voice frames comprises: extracting predetermined features from a voice frame among the plurality of voice frames, and determining whether said voice frame is from a voiced sound, an unvoiced sound, or background noise.