2. The method of claim 1 wherein each of the semantic concept detectors determines the preliminary semantic concept detection values responsive to an associated set of audio features, the audio features being determined by analyzing the audio signal.
2. The method of claim 1 wherein each of the semantic concept detectors determines the preliminary semantic concept detection values responsive to an associated set of audio features, the audio features being determined by analyzing the audio signal. 3. The method of claim 2 wherein the particular audio features associated with each semantic concept detector are determined during the joint training process.