{HEAD ~ an analog} to {TAIL ~ digital converter} that converts an analog acoustic input signal into a digital input signal 
{ HEAD ~ an analog } to { TAIL ~ digital converter } that converts an analog acoustic input signal into a digital input signal
HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH