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