In this paper, aerodynamic sound generation from an isolated helicopter rotor blade system is investigated with the intention of employing the acoustic prediction mechanism in conjunction with design and optimization schemes. Emphasis is placed on airfoil shape optimization resulting in a helicopter rotor blade system that generates the lowest noise for specified conditions. Ffowcs Williams-Hawkings equation is used to predict aerodynamically generated noise from a helicopter rotor blade system. The design aspect of the work deals with designing a rotor airfoil to reduce the aerodynamic noise produced by helicopter rotor blades. The airfoil shape design methodology requires the integration of three distinct modules - a shape parameterization function, an aeroacoustic solver and a search agent for shape optimization. The geometric shape design module uses the PARSEC parametrization method which characterizes the airfoil geometry as a finite number of parametric control handles. These parameters form inputs to the optimization algorithm, which when coupled with the acoustic prediction code, gives an optimally designed airfoil. The simulated annealing algorithm is used as the search agent. Results of the reduction in the predicted noise levels for three optimization cases are presented. Results are also provided for noise optimization with an aerodynamic constraint. Effects on the acoustic predictions for different blade design parameters such as chord length and tip modifications such as sweep and taper are discussed. Copyright © 2016 by the American Helicopter Society International, Inc. All rights reserved.