through the setnchannels() or setparams() method
_sampwidth -- the number of bytes per audio sample
          set through the setsampwidth() or setparams() method
_framerate -- the sampling frequency
          set through the setframerate() or setparams() method
_nframes -- the number of audio frames written to the header
          set through the setnframes() or setparams() method

These variables are used internally only:
_datalength -- the size of the audio samples written to the header
_nframeswritten -- the number of frames actually written
_datawritten -- the size of the audio samples actually written
c