Is there a published way to set the TN for listen checks trying to hear a drone?

Signature, I would guess, is a good starting point.

Yes, the sig.

So there's no published method?

As far as I know, the published canon method is to use the signature, as has been said.

SIG

The SR3 mainbook says that the signature of a standard player character is 6. So a jet-powered vector thrust aircraft with a signature 8 is quieter than your average pedestrian?

Yes, by canon. Noone here says it makes any sense, but that is how it works.

Sig isn't only audibility. Its a combonation of all senses to detect something.

Which of course, works cannonically that its what you need with any sense to notice it.

Well, it is the 21st century... maybe they have since invented new stealth jet engine technology.

There's more to signature than just noise.

Admittedly I don't have my book with me, but I don't remember any references to using sig as a target number for perception tests. References to signature (IIRC) only apply to sensor tests. Is there a page or an erratta that I'm missing?

If Sig = TN it would take a perception (6) test to hear a person walking. But from what I can tell the base TN to hear someone walking is 4.

You specifically asked about Drones. People are a different matter, covered under the perception rules.

You might also consider that while you can hear the sound of a jet airplane or a helicopter, that isn't the same thing as knowing exactly where it is in the sky.

Say you have a vectored thrust drone with a sig of 8.
The GM has you make a perception test with a TN of 8, possibly modified by cyberware, adept powers, the situation (gunshots and police sirens) etc.

You get no successes, so the GM might say "you hear a noise, but its hard to distinguish from the background noise of the city." or the GM might say nothing at all because you failed to detect the drone.

You get 1 or more successes and you definately hear the sounds of vectored thrust engines and you can approximately tell where they are located. If you have a valid line of sight to the drone or you have some reason why you should be able to see the drone (thermal vision, perhaps) then the GM would say you spotted it.

That's my 2 cents anyway.

Yes, finding an aircraft's location in the sky can be difficult, especially if its behind a building. But finding a drone's location on the other side of the door (the only place it could possibly come from) is not as hard. Tying it directly to sig means that it is harder to find the location of an aircraft if it is behind a door than it is to find it in the sky.

I agree that signature is a good place to start, but just blindly using sig ends up with some pretty dumb things happening. I was hoping there would be a bit more discussion of the issue in a book I don't have (like Rigger 3) so I could just say: "this is howit works". I can of course say that, as I'm the GM, but I prefer to use actual rules when they exist.

And oh yeah: Hi SBF! I was wondering when I'd see you here.

That's where all the Perception TN modifiers come in.

Fortune: the TN modifiers are what makes it incredibly hard for a standard human (unaugmented intelligence of 3) to not hear a GMC Banshee firing up its engines on the other side of a 5' wide hallway.

Yes, GM's can and should make judgement calls on TN modifiers when necessary, but something so basic as perception tests to hear drones should not have to vary from group to group as a house rule.

I have to agree that using signature to indicate the stealthiness of vector thrust drones really bothers me. I played a rigger character who ended up with a Ares Guardian vector thrust drone that I used as my primary drone for indoor work. It has a signature of 7, but I just couldn't accept that a body 2 armor 12 drone that was using vector thrust to hover along a hallway could in anyway be described as stealthy. I've been at air shows with a Harrier hovering nearby, and know that is just nonsense. Even if the 206x engines were quiet, the air currents would scatter paper, furniture, suspended ceiling tiles, etc.

Thus when funds and contacts became available, my rigger developed a tracked drone with rubberized treads and a manipulator arm for indoor work. My suspension of disbelief worked again, and I had the added benefit of being able to open doors, select floor numbers on an elevator, and it even was configured to handle stairs.

From SR3, p. 133
"The Signature Rating indicates a vehicle's vulnerability to electromagnetic or thermal detection and serves as the target number for sensor and missle to-hit tests made against the vehicle."

The base TN for hearing, or any perception test is 4; and a table on p. 232 has guidelines for modifiers to the TN.

Hearing a drone starts at TN4. No house rules required.

So entropy, the TN to hear my electric micro drone that looks and flys like a hummingbird is 4? How about the micro spider drone walking along carpet? Those are all TN 4?

Yes, it starts at 4. But there are no guidelines about where to go from there.

Sure, you can say that a VTOL aircraft is a -10 to the target number (given their noise levels in RL). But how do you determine the modifier for a steel lynx, or any of the other countless numbers of drones that the average man on the street doesn't have any clue about because they don't exist?

Then why ask if you knew the answer (or had a specific one in mind) all along? I didn't look it up because I don't have the book(s) in fromt of me. I just assumed (silly me) that the plethora of people that agreed on the signature answer were actually correct.

Maybe you modify it by the signature in some way. Or the GM could (gasp) use common sense to set an appropriate TN modifier.

How do you use common sense to determine target number modifiers for things that don't exist? "Common" sense applies to things that are, well, common.

I asked because its plain as day that you can't just use the signature numbers, because it makes some vehicles and drones pathetically hard to hear.

I don't know the answer, nor do I have one in mind. I just want an answer that doesn't result in outlandishly foolish scenarios, and preferably involves as few calls to test my knowledge of nonexistent objects and my "common sense" has no idea what a steel lynx sounds like. I can guess yours doesn't either, and have a pretty good chance of being correct.

While true that the sig can lead to outlandishly foolish scenarios, using the base TN 4 can as well.

Make a ruling. As long as you are consistent on such a ruling throughout the game, there really shouldn't be a problem. The signature of a drone can (sometimes) give you a basic idea of how loud it is. If not, then use common sense to determine its modifiers in your game.

There's no reason TN modifiers can't vary from game to game, barring a canon standard ... as long as the specific GM's rulings are seen as consistent.

A Steel Lynx travelling at a crawl might very well be quieter than one going at full tilt down an echoing, concrete-encased corridor.

With a human's signature of 6 as comparison, I was thinking maybe making an open piloting test and subtracting [6 - signature or 6 (whichever is lower)] from the TN# for the perception test as long as the vehicle is not moving faster than half it's acceleration rating (which is the rough equivalent to the speed of a human walking slowly in many cases). This would also be a good way to see if characters can hear the sedan creeping up behind them on the street that's about to attempt a drive-by. I wouldn't allow stealth as a complimentary skill in this case since it would be a bit unbalanced. Just my thoughts. Everyone's input on this topic is greatly appreciated.