Ultrasonic　methods　are　used　in　a　wide　variety　of　applications　including　medical　studies,　geological　mapping,　and　nondestructive　evaluation　(NDE)　tests.　In　the　field　of　ultrasonic　NDE,　it　is　necessary　to　treat　inverse　problems　of　various　types.　The　objective　of　this　paper　is　to　predict　the　flaw　response　in　an　inhomogeneous　solid　medium.　A　mathematical　modelling　of　the　testing　situation　is　very　valuable　for　a　number　of　reasons.　The　modelling　helps　in　developing　physical　intuition　and　in　the　interpretation　of　tests.　Multi-Gaussian　Beam　(MGB)　model　is　used　to　represent　the　incident　ultrasonic　beam.　The　effect　of　ultrasonic　attenuation　and　phase　velocity　dispersion　due　to　grain　scattering　is　included　in　the　predictions.　The　variation　of　received　voltage　is　analyzed　against　the　distance　of　the　flaw　from　the　transducer　for　different　dimensions　of　a　square　cylinder　void.　The　effect　of　variation　of　mean　diameter　of　the　grains　on　the　received　voltage　for　different　domain　of　interest　is　also　studied.