This study has been undertaken in order to develop a new nanocomposite acoustic material via incorporation of multi-walled carbon nanotubes (MWCNTs) into the conventional damping material–polyvinyl acetate (PVAc). Usually MWCNTs are added into polymers to strengthen its stiffness only. Here, properties of stiffness and damping are both required for the cone/diaphragm to improve sound features of the speakers. The work provides perspectives on MWCNT covalent modification and the effect of MWCNT surface chemistry on the acoustic performance of the nanotube composites.