Hearing & Distinguishing Specific Heartbeats

[NineDaysDead]

Originally Posted by JCurwen3

@Fred Brackin & NineDaysDead:
Thanks for those links, they are extremely helpful!
@Bruno:
Thanks for pointing me to the High Tech hearing table / rules. Much better / more helpful than the one in Basic Set. Also reminded me of some additional Sense Modifiers rules in Mysteries.

So I think I'm close to my goal.


That may be true. But GURPS has a Detect Lies skill, and with enough points in that skill you can get a far better than 70% accuracy without (1) a polygraph or (2) the benefit of actually hearing that their heart rate increasing. Also, I've seen polygraph experts at work, and although the machine is very important, much of the time the polygraph expert is basically using intimidation / interrogation thinly veiled as an innocent line of questioning; they can seem a bit like mild bullies.

I thought for the ability to detect lies, I'd add Empathy (Sense Based, Hearing) to the build, which would give a +3 to Detect Lies and other relevant skills that would also make sense to get a bonus. To be good at it, they'd need to invest in Detect Lies, but the +3 would make it easier. On the other hand, without investing in that skill, based purely on their superior hearing they could at least hear that the heart rate had become faster... which could mean anxiety, lying, arousal, fear, other emotional state that gets the heart racing, they just physically exerted themselves... or they have some heart problems. Situationally, one could make inferences, of course without any necessary guarantee you're right.

Have you seen this:

Originally Posted by GURPS Supers; Page 108; Reading The Hearts Of Men; last paragraph

Another option is to take the Emotion Sense enhancement of Discriminatory Smell, with the resulting bonus to skills. GMs may choose to allow a similar enhancement to Discriminatory Hearing, representing the ability to hear a person’s or animal’s tone of voice, breathing, and heartbeat; this should also require being within 2 yards of the subject.

So that would be Discriminatory Hearing (Emotion Sense +50%; Profiling +50%)[30]

Originally Posted by JCurwen3

Of course, though, you're probably right about it requiring more than a minute to memorize an individual heart's signature, especially since the heart rate whilst studying the target might be significantly slower or faster than when you "listen" for them later; that wouldn't make it impossible, but it would make it more difficult. I guess I could add Reduced Time to Discriminatory Hearing to make it faster to memorize - maybe 60 times less to reduce normal memorizations to take a second and then a minute or a so to memorize heart signatures. Alternatively, I could have an -80% limitation on Photographic Memory for just sampling hearts... which I think would cover quick, effective memorization of heartbeat signatures. Or, I could go even simpler and call it a perk to memorize a heart's unique sound quickly, say, within a minute.

With Profiling +50% you won't need Photographic Memory:

Originally Posted by Powers page 47

As a side benefit, all attempts to memorize new signatures succeed automatically – there’s no need for an IQ roll. +50%.

[Bruno]

Originally Posted by JCurwen3

It's not clear to me though where the short list of background noise penalties (busy street -5, blaring TV -6, fireworks -10) came from, and why those things aren't in the table, listed with dB values and ranges.

Normal traffic is on the Basic Set table at 16 yards (p358), which is dB(A) 100, "Air gun, firearm firing "Silent" ammo, revving gas engine" in High Tech.

[JCurwen3]

Originally Posted by NineDaysDead

Have you seen this:
So that would be Discriminatory Hearing (Emotion Sense +50%; Profiling +50%)[30]
With Profiling +50% you won't need Photographic Memory:

Thanks! That's perfect. I'm a little surprised the book requires only 2 yards distance though. Seems a bit too far away, even after the +4 to hearing rolls that Discriminatory Hearing provides. It's also not clear if 2 yards is for someone with a total Hearing of 14 (base Per 10 with the +4 bonus)... I'd assume this would be need to be at a closer range if your Per was lower, and that the allowed range would be greater with higher Per or extra levels of Acute Hearing. That's how I'd play it anyway.

[Joel]

I think greater/shorter range for the hearing-based empathy would simply be based on if you took Increased Range enhancements on it or not, that's certainly how I'd do it for Discriminatory Smell with Emotion Sense.

[vicky_molokh]

Originally Posted by JCurwen3

No, that sounds about right and is consistent with the rules. About as harsh as reality... at least I think it sounds realistic (pretty unfamiliar with the actual realities of hearing at a distance and through background noise, but I assume that the hearing rules are at least loosely based on reality).

Okay, perhaps. But I find it dubious that if we have no other noise in the room (-0), it still takes Hearing 14 to have a 50/50 chance to notice that someone is talking 16 yards away.

[JCurwen3]

Originally Posted by vicky_molokh

Okay, perhaps. But I find it dubious that if we have no other noise in the room (-0), it still takes Hearing 14 to have a 50/50 chance to notice that someone is talking 16 yards away.

Heh, yeah, I share your doubts. I routinely hear the exact details of people's conversations through both a thin door and at about 16 yards distance, often whilst I'm playing a video on my PC at a low volume. Still, that not might be average. With no noise, and with them in the same room, and with the only requirement being that you actually just hear that there is a conversation (without hearing the details)... hearing this at 16 yards away seems like it should have significantly better that 50/50 odds for human average Hearing 10. Then, again, I'm no expert on the statistical performance of human hearing tasks, and my own experiences may not be typical.

[Anthony]

Sound propagation is complicated, and the GURPS rules on it are a rather crude approximation.

[Bruno]

Originally Posted by Anthony

Sound propagation is complicated, and the GURPS rules on it are a rather crude approximation.

*nod* if our world of light was like our world of sound, we'd live in a crazed funhouse of polished metal, shiny ceramic and glass, mixed randomly in with fluffy and matte black surfaces. The things going on with reflection, absorption, and transmission of sound in a home environment is just nutty.

It's more consistent in some kinds of natural environment, but only some. Acoustics in the ocean make my brain hurt.

[NineDaysDead]

Originally Posted by JCurwen3

Thanks! That's perfect. I'm a little surprised the book requires only 2 yards distance though. Seems a bit too far away, even after the +4 to hearing rolls that Discriminatory Hearing provides. It's also not clear if 2 yards is for someone with a total Hearing of 14 (base Per 10 with the +4 bonus)... I'd assume this would be need to be at a closer range if your Per was lower, and that the allowed range would be greater with higher Per or extra levels of Acute Hearing. That's how I'd play it anyway.

I'd say PArabolic Hearing should certainly double that 2 yards, given the cost.

[Flyndaran]

Originally Posted by Bruno

*nod* if our world of light was like our world of sound, we'd live in a crazed funhouse of polished metal, shiny ceramic and glass, mixed randomly in with fluffy and matte black surfaces. The things going on with reflection, absorption, and transmission of sound in a home environment is just nutty.

It's more consistent in some kinds of natural environment, but only some. Acoustics in the ocean make my brain hurt.

Cats have much better hearing than humans. But I know where sounds come from better than they do, because I know of some oddities of echoes and distortion.