Why does a person diving under the water not hear noises on the river bank, although the water conducts sound well?

Water conducts sound well – its speed of propagation in it is several times higher than the speed of its propagation in air. But for this, for the propagation of sound, its source must be in the water.

In our example, all the noises on the river bank are generated by sound sources in the air.

Therefore, for a person under water, water will not play the role of a sound conductor, but, on the contrary, a sound insulator. Airborne sound waves of coastal noise will propagate over the water surface and, due to their insignificant power, will not be able to make the water mass of the river “sound”.