No, the amplitude of a sound wave does not decrease when it passes through a denser medium. In fact, the amplitude of a sound wave remains constant as it travels from one medium to another, assuming there are no losses or changes in energy along the path.
When a sound wave propagates through different media, such as air, water, or a solid, its speed and direction may change due to variations in the properties of the medium, such as density and elasticity. However, the amplitude of the wave, which represents its maximum displacement from the equilibrium position, remains unaffected.
The change in density or medium may affect other properties of the sound wave, such as its wavelength or frequency. For example, when a sound wave travels from a less dense medium to a denser one, like from air to water, its speed decreases while its wavelength decreases and its frequency remains constant (according to the equation v = f * λ, where v is the wave speed, f is the frequency, and λ is the wavelength).
To summarize, the amplitude of a sound wave remains constant when it passes through a denser medium. Changes in the medium can affect other wave properties, such as speed, wavelength, and frequency, but not the amplitude.