1. A voice detector identifying a current input voice signal comprising: a long-term averaging circuit for calculating a long-term weighted average value of the current input voice signal; a short-term averaging circuit for calculating a short-term weighted average value of the current input voice signal; a level identification circuit for identifying a noise level based on the long-term weighted average value and the short-term weighted average value and outputting a discrimination level indicative of the identified noise level; and a voice discriminator for comparing the long-term weighted average value with the discrimination level and determining whether the current input voice signal is a voiced term or an unvoiced term based on a result of the comparison.