1. A method of initializing an ITU Recommendation G.729 Annex B voice activity detection (VAD) device, comprising the steps of: extracting a set of parameters from a signal that characterize said signal; calculating an energy measure of said signal from said set of parameters; comparing said energy measure with a reference value; determining an initial value for an average of a noise characteristic of said signal; and counting the number of times said energy measure equals or exceeds said reference level.