Vibration response of gears is an important indicator for gear mesh analysis as its value has been found to changing drastically with increase in number of cracks in gears. In the current study, the effect on vibration response for healthy gear and cracked gear has been investigated. High frequency amplitude modulated signal is taken as input and provides an output which is envelope of the original signal. ANSYS 20 software, MSC ADAMS along with MATLAB have been used to model the gears with multiple cracks induced. Structural analysis has been performed through Mechanical APDL. The vibration response values have been found to vary significantly with increase in number of cracks.