As shown in FIG. 17D, the high pass filter 1758 receives the speech signals 1706 and transmits the high frequency components 1768 (components with a frequency higher than a certain threshold frequency) of the speech signals 1706 to the actuator signal generator 1776 and attenuates (filters out) the frequency components of the speech signals 1706 with frequencies lower than the threshold frequency. The high pass filter 1752 may be implemented in the form of a first-order electronic high-pass filter by placing the input speech signals 1706 across a series combination of a capacitor and a resistor for conditioning signals prior to analog-to-digital conversion, or as a discrete-time washout filter, or a digital filter. The high frequency components 1768 of the speech signals 1706 are used by the actuator signal generator 1776 to determine a high frequency signal power of the high frequency components 1768 of the speech signals 1706 and generate the actuator signals 1718, as described below with respect to the actuator signal generator 1776.
