Echo rules: weird interactions creating DareDevil?

[Jowgen]

Races of Stone has a use for the listen skill that, with a DC 25 listen check, lets you determine the distance between yourself and the source of an echo within 10% accuracy.

This gives me a headache.

First, when and how something creates an echo is utterly undefined in the rules. The RoS fluff suggests it's meant for underground caverns/tunnels; but that's all I know off. No mention of how loud a noise or what kind of noise produces an echo, or how far that echo can actually travel. If the DC 25 was variable depending on the sound, then that would solve this, but there is no such mention.

Second, this entire concept blasts a big hole in the rules for distance listen penalties. I can see no way to reconcile the standard -1 listen penalty per 10 ft of distance with these rules for hearing things via echos. Considering that there are no rules for how far echo can travel, there is no way to apply a range penalty.

Third, how is hearing an echo supposed to interact with other uses of the listen skill? If you make a DC 40 check to hear the echo of a conversation, do you then understand the conversation? DC 45 to to pin-point the echo-making creature rather than with 10%?

Or lets add the Keen Eared Scout feat. Beat the DC 25 for the echo by 5, and you get "the size, speed, and direction of the source of noise". Beat it by 10 and you get "the precise, current position of the creature or object that caused the sound". If there is someone on the other side of a labyrinth, and they make a loud noise that echos to you, and you make a DC 35 listen check... what the hell do you end up knowing about the creature, or at that, the walls of the labyrinth that have produced the echo? Does having a high listen plus Keen Eared Scout in an underground environment arguably give you DareDevil-grade echolocation, allowing you to throw rocks into caves to hear the lay-out of the tunnels?

So yeah, if anyone happens to know any obscure rules, examples, creature abilities or spells that have anything that might be related to this conundrum, I'd be much obliged.

[Chronos]

It's not for hearing other things via their echoes. It's for hearing the echoes themselves. In order for the feat to work, you have to be able to also hear the source, which may even be yourself. Example: You clap your hands, and you hear an echo of your hands clapping. Based on hearing both, you can determine how far away the wall is.

[Jowgen]

It's not for hearing other things via their echoes. It's for hearing the echoes themselves. In order for the feat to work, you have to be able to also hear the source, which may even be yourself. Example: You clap your hands, and you hear an echo of your hands clapping. Based on hearing both, you can determine how far away the wall is.

Hmmm... not sure I entirely follow your logic. Are you saying that it's echo itself is that is being heard, not a different sound transmitted via echo? I can see the "source of the noise" or the "creature or object that caused the sound" being defined as the walls/ceilings that "sourced/caused" the echo through reverberation. Your example certainly makes sense based on how blind people can actually use Echolocation (http://en.wikipedia.org/wiki/Human_echolocation) to perceive objects. And, thinking about it, this takes care of the distance penalties, in that there is no distance between you and an echo that has reached you.

However, I don't quite see why there'd be a distinction between the wall-source and the original-creature-source for the purpose of additional information. It is entirely possible to understanding echoing conversation (see the Temple of Heaven in Beijing), which is additional information gained by beating the DC by 15, so what is stopping the D&D-science transmission of the other additional information (i.e. size, armor, etc.)?

[Chronos]

Understanding echoed conversation (if for some reason you can't hear it directly) is a different Listen check from trying to figure out how far away the wall is. It'd be just the same as trying to understand it directly, except that the relevant distance would be the total distance from you to the wall to the creatures talking (with perhaps a circumstance penalty if the wall is irregular). At least, in the case where there's no special circumstances like an ellipsoidal echo chamber: If you and the other creatures are at the foci of such a chamber, then I'd treat it as no distance penalty at all, no matter how far apart you actually are.

[Jowgen]

I can see where you're coming from with the total distance, but I'm not sure I'd agree.

If you make a DC 0 check, you hear the conversation. Beating that DC by 15 means you understand what is being said. If you make a DC 25 check, you hear the echo of the conversation. In both cases, the base DC lets you hear that there is a conversation, why wouldn't the same beating the DC by 15 apply in the case of Echo?

Also, I propose this attempt to reconcile some of the rules: The only time you can make the echo listen check is if an echo reaches you. There is no distance between yourself and the echo. The echo isn't treated as a far away sound you hear despite distance, it's a sound in the immediate vicinity that's hard to hear in a meaningful way due to its nature (hence the high DC). This view would solve the issue of the absence of distance penalties from the echo rule.

[Chronos]

I don't know what you mean by "There is no distance between yourself and the echo.". There is no distance between you and any sound you hear: The fact that you're hearing it is proof that the sound has reached your ears. But there's still a distance between you and the source of the sound, which is what matters for the Listen skill.

[Jowgen]

I don't know what you mean by "There is no distance between yourself and the echo.". There is no distance between you and any sound you hear: The fact that you're hearing it is proof that the sound has reached your ears. But there's still a distance between you and the source of the sound, which is what matters for the Listen skill.

How to put this... the idea is that echos are different from normal noises in regards to how they're treated for the purpose of the listen skill. Normal noise has a distance penalty because travelling noises loose power over distance. Certain environments can either increase or decrease this distance penalty. Echo-conductive environments are special in that they create sounds that transmit regardless of distance (hence no distance penalty), but are difficult to properly hear due to a decrease in power inherent in the process of echo-transmission (hence DC 25).

The reason why I believe this to be a rules-appropriate rationalization is as follows. Normally, as soon as a sound originates more than 10 ft away, it becomes harder to hear. The Echo listen check, however, completely disregards this mechanic in its description. It doesn't matter how far the original source or the wall(s) creating the echo are away, the DC remains flat 25, and the check can always be attempted within reach of an echo.

Therefore I believe that for the purpose of adhering to the rules and keeping them consistent, an echo can not be treated as a noise that originates from far away, but instead must be treated as a special acoustic phenomenon that occurs in specific areas under specific conditions. So if you are in that specific area when an echo occurs (arguably within 10 ft of it), you're not listening to a far away noise reaching you, but to a special acoustic phenomenon that is ocuring in your immediate distance.

Another way of putting is that the noise contained within an echo doesn't travel in the distance-penalty-incurring-way, but is instead transmitted in a special echo-penalty-incurring way, which sets the DC to properly hear the echo at a flat DC 25 as opposed to the normal DC loudness+distance.

Am I making sense? :smallconfused:


EDIT: On a different note, there is still the issue of what environments and what noises can create an echo. Unless anyone contributes a piece of rules-text that I'm not aware of, this is fully DM territory. Based on the above, I'd personally gravitate towards homebrewing a system where different areas have varying levels of echo-conductivity (LEC), which determines how quiet of a sound they can echo within their confines. The easiest way to quantify these LECs in my mind would be to directly equate them to Listen DCs. A winding stone tunnel, for example, could have an LEC of 15, meaning that it can only produce audible echos for noises that could normally be heard with a DC 15 or lower listen check. An area that can echo sound perfectly (http://en.wikipedia.org/wiki/Whispering_gallery) would have an LEC of 25 (the echo DC). Sounds that are higher than DC 25 could only be echoed in areas that can actually amplify sound (http://en.wikipedia.org/wiki/Acoustic_mirror).

Does this sound like a reasonable way to adjudicate echo environments?