The phone would be able to understand that a sharp decrease in volume has taken place, while at the same time the user would make a gesture on or near the device's screen. Based on an illustration that accompanied the filing, one of the gestures would involve the user cupping his mouth with his hand as though he/she was whispering in the ear of another person. For those who use their handset to discuss discreet matters, this might come in handy.
The filing was made with KIPRIS (Korean Intellectual Property Office) on July 16th, 2014, and the exact title of the application is "Method And Apparatus For Recognizing Whispered Voice." And no, we don't expect this technology to show up in the Samsung Galaxy S7.
source: KIPRIS via GalaxyClub.nl (translated)