Compatibility of polysaccharide-based natural polymers, xanthan gum (Xn), tragacanth gum (Traga) and acacia gum (Ac), with synthetic polymer, polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) in aqueous solution has been investigated using the related acoustical parameters at room temperature, 303 K. The concentration of synthetic polymers PVP and PEG was varied to understand the nature of solute-solvent interaction in the polysaccharide-based natural/synthetic polymer in aqueous solution. FT-IR studies were also carried out for vibration assignment and confirmation of compatibility. (C) Koninklijke Brill NV, Leiden, 2010