[REQ] Realistic "Ping" (not movie ping)
 

I have been reading up a bit about ASDIC.

It seams that almost all ADSIC was between 16khz and 24khz. Almost never lower
than 4Khz.

Now, thats very, very high frequency. Humans can't hear above 20khz, most people
can't hear much above 16khz. (you can (or can't!) hear a sample at 16khz HERE)

This means that the "ping" sound you hear in the game is bunkum!
It's just not like that at all unless you have equipment to lower the frequency.


That does not mean that you can not hear the high-pitched ping at all in a sub, but
what ever it sounds like, it wont be a "Ping".


Does anyone have any clue what ASDIC would sound like from inside a sub if
it could be heard at all?
I would guess that the ping would cause some lower frequency sounds as well.

Would anyone like to have a go at making a truly realistic ping?



So far the only lead I have is from Steve who says he read the sound was
like:"gravel being thrown against the hull".

In that same thread didn't someone who had served on a sub say it sounded like a 'click'?

Why can't I find that thread now? It was just today.:cry:

Well in some of the books I've read the U-boat Crew describes asdic as "pebbles dropping on hull",:x but that don't sound good! Give me the movie stuff anyday!:yep:

Good lord... why did I read this?

Repeat: do not start in the top third of the chart.

I've gone STRAIGHT to that ping on the top right corner, the louder one...

Jeez... My ears are not functioning properly, and at the time it was almost painful... a weird feeling.

But I did hear it...

By the way... If having a real ping on the game means listening contantly to that disturbing sound, capable of hurting your ears, than no thanks! :up:

Agree!

Another report stated that it sounded like steel wires being dragged along the hull.

And how the hell would they now what sounded like steel wires being dragged along the hull? :lol:

At a guess, I would say that this wire/gravel sound is formed in the same way as if
you put a >20khz tuning fork against a sheet of metal.
You can't hear the sound the tuning fork is making, but you can hear the fork
bouncing off the metal.


It might also be the sub's own harmonic at play. Think of knocking the tuning fork you
can't hear against one you can. However, I rather doubt this. Sub's are big bells to ring
and I don't think a 120-200dbl ping is enough to do it.




To Laboe with steel wire, gravel and a microphone?


We can either skip that part of the sound altogether if we claim the ping is above 20khz or we can play it very quietly.

Sooooo, throwing gravel was more commonplace? :lol:

"Captain, were out of depthcharges, what should we do?"

"......Ummmmm, let's throw some dirt at those Jerry mongrels.":arrgh!:

That 16 kHz sound sounds like the noises I hear when the tv is on or with certain music and sounds on games. It's annoying as hell and no one else seems to notice it but me. I can tell if someone has the tv on two floors down and several rooms over, lol.

:rotfl:

Re Movie Ping
 

Hi All,
The 'Ping' beloved by movie makers is the sound which the operator hears and also comes out of the speakers. Because most normal hearing cannot detect those frequencies the incoming sound is mixed with another frequency 1k/c lower or higher than that transmitted, this results in a 1 k/c note still bearing all the characteristics of the original, pitch, doppler etc. The process is known as heterodyning. The sound heard in the submarine when the beam struck the hull was sort of a click/squeak. The reducing interval between these indicated they were in contact and of course the decreasing range, giving a good skipper some idea when to take avoiding action. Because of this Hunter/Killer groups devised a creeping attack whereby one ship held contact but used constant transmission interval while the others formed a line and virtually carpet bombed the target, hence their high rate of success.
RR

thx for the definitive answer.

also, i think british ww2 asdics operated at 14khz.

I remember in Silent Hunter I when the Japanese pinged you it had a trilling sound like the bell on a kids bicycle. I wonder if the "trill" is what they mean by a gravel sound? My buddy who was on a navy supply ship in the 90's said his ship was pinged by sub at close range and it knocked him out of his bunk! It's kind of a letdown though to find that the pings are not authentic.

what about this one:
http://www.liverpoolmuseums.org.uk/m...boa/asdic.aspx

btw, i read in a book from a german ww2 sonar man that
they picked up the asdic sounds first in the hydrophone,
then after some time it was heard in the whole boat.
he also described the sound as a high-pitched trilling
(in the hydrophone).

We need to keep in mid that the frequencies traveling tru the plancton, salt and thermal layers and there is of cause the pressure-hull this always makes the ping sound a bit off.

I'd say lets stick to the "pepples on a hull" and movie version. The real ping frequencis will damage you ears! :hmm:

Well, I suppose the second best solution is just to remove the ping altogether.

I can't listen to it now that i know its fake.

maybe it sounds more like this:
http://www.uboataces.com/ref-sonar-sounds.shtml

don't know if it's meant to be inside the sub,
but it sounds close to the descriptions i read
about.

OK, let's make some things clear: The human can't listen to sounds behind his frequency limits, that's correct BUT:

1.- If the source which produces that sound also creates a colateral sound in the frequency heard by the human, then you BET you will hear something. An example? Quite easy: Dolphins and bats. You CAN hear a very high pitch and short scream when they emmit their ultrasonic waves, yet you don't of course hear the waves themselves. You just listen to the secondary sounds produced by the air expelled through their organs who makes them vibrate and emmit the impuses So the ping we hear in naval sims is correct in that it represents the audible part of the electromagnetic impulse made in the sonar dome (Which is made of metal itself), more or less the same as when hitting a bell.

2.- The "gravel rattle". This has been told in many accounts of submariners, I can right now indicate if memory serves me well, Richard O'Kane f.e.

That gravel rattle along the ship is the result of the ultrasonic impulses hitting a metallic empty tube (The submarine) and as such causing a vibration (As well as being reflected to their origin, thus allowing the ASDIC to show the echo or return). The frequency with which the metal vibrates IS audible by the humans, and hence the comment about the gravel rattle.

Hope that makes it all much clearer :up: