{HEAD ~ The apparatus} 4, wherein {TAIL ~ the first log power spectrum F} is computed by the following equation: 
wherein
{ HEAD ~ The apparatus } 4 , wherein { TAIL ~ the first log power spectrum F } is computed by the following equation :
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH