Studies on the process of acoustic stimulation in prenatal period require to assess the beneficial condition for child development, as well as characteristic sounds which could negatively affect the development of auditory system, brain or even entire body. It can be provided with the simplified model of sound attenuation in the uterus, which can be represented by first order passive low pass filter. On the basis of total harmonic distortion analysis for a single sound, a proposal indicating the sound reduction in the intrauterine environment is formulated. It is hypothesised that the sound stimuli in the uterus is not the same sound as the music in the source.