Methods and systems of barrier evaluation are disclosed. The method includes obtaining vibration measurement data measured in a wellbore having at least one casing. In addition, the method includes determining a boundary definition of the barrier between the casing and a formation, based on the vibration measurement data. Further, the method includes evaluating the barrier based on the one boundary definition. The system includes a vibration sensor located in the wellbore having at least one casing and a vibration source for generating vibrations. The system may also include a data logging system of producing vibration measurement data received with the vibration sensor and a processor for determining at least one boundary definition of barrier between the casing and a formation, based on the vibration measurement data and evaluating the barrier based on the at least one boundary definition.