Systems and methods for adaptive sidetone and adaptive voice activity detect (VAD) threshold for speech processing are disclosed. The VAD system generally includes an adaptive VAD threshold generator configured to generate a VAD threshold based on an increase in voice level resulting from sidetone attenuation and a comparator for comparing received signals to the adaptive VAD threshold to determine the existence of voice activity. The sidetone attenuation is based on an average ambient noise energy level determined from a noise energy amplitude during periods of no voice activity and a comparator for comparing received signals to the adaptive VAD threshold to determine existence of voice activity.