why no rebound sound ?

[Kpt. Lehmann]

Originally Posted by Pisces

Well, not quite. You can hear a difference in the sound around you when you are standing next to a large flat building. Those secondary paths of the sound come in delayed from the direct path, but weaker. This could also happen underwater I think. But I am no sonar technician.

The situation I refer to is the most common scenario in the open ocean where it is deep and where there is pretty much nothing else to reflect the pulse. I realize that there are a few exceptions, but they are not generally common.

Hearing a double ping from within the sub.... that's mostly Hollywood.