FIG. 12F illustrates an example representation of calibration data as a graph using a cutaneous actuator as in FIG. 12E, according to an embodiment. In the illustrated graph, an input frequency 1288 into the cutaneous actuator, such as cutaneous actuator 1266 is plotted on the horizontal axis, and a subjective magnitude 1286 of the haptic output is plotted on the vertical axis. The cutaneous actuator in this case may provide a vibrational haptic output. As the frequency of the vibration increases, as shown in the input frequency 1288 axis, the subjective magnitude 1286 that is perceived increases. In one embodiment, the subjective magnitude may be measured as above, i.e., in accordance with the user's perception of the strength of the haptic output. For example, in the illustrated example, the subjective magnitude is measured by first determining, at a given input frequency 1288 for the cutaneous actuator, a minimum amplitude of voltage to the cutaneous actuator where a user may detect the haptic output (the vibration) at least 50% of the time over multiple tests. At this level, the detection of the user is measured in decibel (dB) relative to a 1 micron peak or dB relative to 1N displacement. In other words, the subjective magnitude is computed as 20*log10(x), where x is the objectively measured force or displacement created by the cutaneous actuator. Over the range of input frequencies 1288, a human detection threshold curve is thus generated. The inverse of this curve is then used as the calibration data 1220 and is the one shown in FIG. 12F. In other words, the subjective magnitude is the inverse of the detection threshold for the cutaneous actuator over the range of input frequencies.
