A new model for noise prediction of hybrid electric aircraft is presented. This model is demonstrated on the parallel hybrid of An-26 aircraft. The power plant of An-26 modification consists of gas turbine engine and electric engine driving propeller through a common gearbox. According to this model, the flight path is obtained using numerical solution of systems of differential equations, which describes aircraft flight dynamics on all flight segments. The simulation of noise is based on trajectory calculation using height-speed characteristics of hybrid power plant. We make each segment of flight path to comply with the limitations imposed by flight operation manual of An-26 through optimization of hybrid electric aircraft performances. Genetic algorithm was used to find global optimum for parameters of the angle of attack function. New criteria for optimization were developed enabling flight with monotonously increasing/decreasing speed and height, level flight, making trajectory angle equal to zero at the end of segment, and reaching specific airspeed or height at the end of the segments. Final turboprop hybrid electric aircraft performances include total thrust and true airspeed, which are used for the evaluation of contours of maximum A-weighted sound pressure level, effective perceived noise levels, and sound exposure levels during takeoff and landing of aircraft.