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