The Free On-line Dictionary of Computing (30 December 2018):

subband encoding

   An audio compression technique where the sound is split into
   frequency bands and then parts of the signal which the ear
   cannot detect are removed, e.g. a quiet sound masked by a loud
   one.  The remaining signal is encoded using variable bit-rates
   with more bits per sample being used in the mid frequency
   range.

   Subband encoding is used in MPEG-1.

   (1994-11-02)