Numerous European countries experience a steady increase in the share of electric (EV) and hybrid electric (HEV) vehicles in the traffic stream. These vehicles, often referred to as low- or zero-emission vehicles, significantly reduce air pollution in the road environment. They also have a positive effect on noise levels in city centers and in the surroundings of low-speed roads. Nevertheless, issues related to modeling noise from electric and hybrid vehicles in the outdoor environment are still not fully explored, especially in the rural road settings. The article attempts to assess the degree of noise reduction around these roads based on different percentages of EVs in the traffic stream. Input data for noise modeling was obtained from 133 sections of homogeneous rural roads in Poland. Based on their analysis, it was first determined on how many of these road sections electric-vehicle-induced noise reduction would be possible, taking into account the traffic speeds occurring on them. Next, a computational algorithm that can be used to calculate noise reduction in the CNOSSOS-EU model is presented, and noise modeling is performed based on it for different percentages of electric vehicles in the traffic stream.