A system and method for evaluating a part-under-test (120) is disclosed. The part-under-test (120) is excited using at least one drive frequency. A first surface acoustical wave (SAW) mode (206) is identified in the frequency response (200). A separate reference peak (204) for the identified SAW mode (206) is also identified in the frequency response (200). At least one degeneracy assessment zone (208) is evaluated for existence of a surface defect trigger condition. If a surface defect trigger condition exists, the part-under-test (120) may be rejected. Otherwise, the part-under-test (120) may be accepted.