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