The envelope encoder 1716 (illustrated and described in more detail below with respect to FIG. 17D) encodes characteristics of the speech signals (e.g., 1706) to generate the actuator signals 1718. In one embodiment, the envelope encoder 1716 extracts a temporal envelope from the speech signals 1706. The temporal envelope represents changes in amplitude of the speech signals 1706 over time. The envelope encoder 1716 generates carrier signals having a periodic waveform. The carrier signals may be sinusoidal or square wave pulse signals. The envelope encoder 1716 generates the actuator signals 1718 by encoding the changes in the amplitude of the speech signals 1706 from the temporal envelope into the carrier signals. The actuator signals 1718 thus carry information from the temporal envelope encoded within the carrier signals. The envelope encoder 1716 may be implemented in software or hardware. For example, the envelope encoder 1716 may be part of a PC, a tablet PC, an STB, a smartphone, an internet of things (IoT) appliance, or any machine capable of executing instructions that specify actions to be taken by that machine.
