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