We report the fabrication of flexible, low cost, and wearable piezoelectric nanogenerators (NG) composed of a poly(vinyl alcohol) (PVA) nanofiber web and <0 0 0 1> oriented zinc sulfide (ZnS) nanorods (NRs) by a facile and scalable electrospinning technique. The piezoelectric performance of the NG is found to be increased by simply stacking the nanofiber web mats, where the ZnS NRs are incorporated in the PVA fiber matrix. Furthermore, we also designed a large area wearable nanogenerator (WNG) to harvest mechanical energy from acoustic random vibrations and convert it into electrical energy, and an improved acoustic sensitivity of 2 V.Pa-1 is observed. This indicates that the WNG is ultrasensitive to random mechanical vibration, and possesses potential utility as a sustainable power source and sensitive pressure sensor particularly suited for portable electronics and wearable technology.