A system determines a power spectral density associated with an audio signal that includes {TAIL ~ a speech signal} and {HEAD ~ a noise signal} 
A system determines a power spectral density associated with an audio signal that includes { TAIL ~ a speech signal } and { HEAD ~ a noise signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD