A method and an apparatus are provided for discriminating between a voice region and a non-voice region in an environment in which diverse types of noises and voices exist. The voice discrimination apparatus includes a domain transform unit for transforming an input sound signal frame into a frame in the frequency domain, a model training/update unit for setting a voice model and a plurality of noise models in the frequency domain and initializing or updating the models, a speech absence probability (SAP) computation unit for obtaining a SAP computation equation for each noise source by using the initialized or updated voice model and noise models and substituting the transformed frame into the equation to compute an SAP for each noise source, a noise source selection unit for selecting the noise source by comparing the SAPs computed for the respective noise sources, and a voice judgment unit for judging whether the input frame corresponds to the voice region in accordance with the SAP level of the selected noise source.