Each of {TAIL ~ the frames} comprises a mixed signal containing a speech signal and {HEAD ~ a noise signal} 
Each of { TAIL ~ the frames } comprises a mixed signal containing a speech signal and { HEAD ~ a noise signal }
OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD