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