An example wearable device includes a haptic actuator to produce an output haptic vibration in response to a target input signal waveform, a haptic effect sensor located in proximity to the haptic actuator to measure a haptic vibration corresponding to the output haptic vibration and to output a measured haptic vibration waveform and a feedback circuit to modify the target input signal waveform to reduce a difference between the output haptic vibration and a measured haptic vibration waveform.