Imaging the inside of the Earth requires knowledge of how the Earth's properties affect seismic recordings. However, certain properties, such as density, affect seismograms in a way that is not fully known. Using numerical simulations, we can calculate a synthetic seismogram for a medium with and without density heterogeneities, and then compare the two signals. That way, we quantify the density effect on a seismogram. We also show that it is visible and growing as the wavefield gets scattered.