yuan2005 implements the envelope onset asynchrony feature described in
Hanfeng Yuan, Charlotte M. Reed, Nathaniel I. Durlach, "Tactual display of consonant voicing as a supplement to lipreading," The Journal of the Acoustical society of America 118.2 (2005): 1003-1015.
The method takes input audio and produces 2-channel tactile output, based on filtering and extracting amplitude envelopes.