The provided conclusion is not right as the speed of sound is much faster in water as compared to the speed of sound in air.
It is because the particles in water are much closer than the particles in the air. Consequently, they transmit the vibrations at a faster rate and thus, sound travels faster.
In addition, the muffling is not associated with the speed of the sound wave in the water. It occurs because human ears are evolved to hear sound in air due to which we hear clear sound in air.
