1. A frame based audio signal classification method, comprising the steps of: determining, for each of a predetermined number of consecutive frames, feature measures representing at least the following features: an auto correlation coefficient (T n ), frame signal energy (E n ) on a compressed domain emulating the human auditory system, and inter-frame signal energy variation; comparing each determined feature measure to at least one corresponding predetermined feature interval; calculating, for each feature interval, a fraction measure (Φ 1 -Φ 5 ) representing the total number of corresponding feature measures (T n , E n , ΔE n ) that fall within the feature interval; and classifying the latest of the consecutive frames as speech based on each fraction measure lying within a corresponding fraction interval, and classifying the latest of the consecutive frames as non-speech based on each fraction measure not lying within the corresponding fraction interval.