This paper proposes lightweight textile acoustic structure, wherein electrospun polyacrylonitrile-based nanofibers enhance sound absorption properties with no weight and thickness penalty. Polyacrylonitrile nanofibers with diameter of 110 +/- 7 nm were electrospun on spacer-knitted fabrics by varying deposition amount and surface coating arrangement. Proposed novel approach eliminated additional processing steps such as handling and post-lamination and provided easy scalability of nanofibers at macro-scale. The results showed that the sound absorption of nano-enhanced specimens was improved drastically when deposited amount of nanofibers or its effective surface area increased. Sound propagation paths in different configurations were interpreted from sound absorption and air permeability measurements. The sound absorption coefficient values up to 0.7 are achieved in the low and medium frequency ranges with no weight and thickness penalty by tuning deposition amount and surface coating arrangement.