Microsaccades are small, rapid, involuntary eye movements that are known to occur during fixation. The majority of microsaccades has overshoot, the maximum swing above final amplitude, which is a characteristic feature of servomechanism (positioning-control system). Recent studies suggested that auditory attentional cues could induce a transient decrease in the rate of microsaccades. This "microsaccadic inhibition" may be due to a fast reflex of the oculomotor system, which can be considered as a positioning-control system. However, it has not yet been investigated whether auditory attention would affect the properties of the positioning-control of the oculomotor system, such as the overshoot of microsaccade. Here, we computed two novel parameters of microsaccades, damping factor and natural frequency, by considering the waveform of a microsaccade as the step response of a second-order transfer function. We used a cue-target paradigm to investigate whether these parameters can be affected by the presentation of auditory attentional cues. Participants were instructed to keep looking at the central fixation point on the computer screen, while listening to the auditory stimuli. We found that the damping factor of microsaccade, which is an indicator of the accuracy in positioning-control, temporarily decreases with the presentation of auditory attentional cues. This result indicates that auditory attention could affect the positioning-control of the oculomotor system.