Why Does Sound from Above the Surface Sound Faint Underwater?

[p834]

When swimming underwater, why does sound from above the surface sound very faint?

I know that the answer to this may be simple, but I just can't put my finger on the answer. I know that sound travels faster in water then it does in air, does this fact have anything to do with it?

Thanks!

 

[A.T.]

Sound is partially reflected at the surface. Your ear-drums are under pressure, thus probably less sensitive.

 

[Bobbywhy]

A.T. above is correct: sound waves are partially reflected from the surface of the water. Also, sound waves in air do not pass into water efficiently. The energy of those waves is so small it is not sufficient to excite pressure waves in water easily. So when you are underwater you will hear very little sound from the surrounding air.

Sound waves propagate through the mediums of gas, liquids, solids, and plasmas. Sound waves in air (gas) form a series of pressure highs and lows. To see good graphical diagrams of these pressure waves see:

http://hyperphysics.phy-astr.gsu.edu/hbase/sound/tralon.html