One of the problems is that the sound you hear in movies is usually the sound an active sonar unit makes when it sends the signal, not what is heard from the submarine. Former u-boatmen usually describe what they heard as "gravel bouncing off the hull", which doesn't seem to me to be a 'ping' at all. There are several different sonar sound mods out there. Most of them were made for SH3, but since both games us .wav files for the non-speech sounds any of them should work with SH5 with no problems.
Here is one a quick search turned up.
http://www.subsim.com/radioroom/down...o=file&id=2762
And another.
http://www.subsim.com/radioroom/down...?do=file&id=42
You might also try downloading some of the other big sound mods. Some of them have different sonar sounds which you can easily grab and install by hand.