{HEAD ~ The system} then determines {TAIL ~ the power spectral density} of the audio signal from the calculated power spectral density of the speech signal 
{ HEAD ~ The system } then determines { TAIL ~ the power spectral density } of the audio signal from the calculated power spectral density of the speech signal
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH