How quiet is it?

[garrowolf]

I appreciate that so many people are interested in sound contrast but I'm just looking for the decibels of people walking on different materials. That's all.

 

[Hand of Evil]

See the math...
Sound and Noise - Characteristics of Sound and the Decibel Scale

 

[Umbran]

I appreciate that so many people are interested in sound contrast but I'm just looking for the decibels of people walking on different materials. That's all.

Due to its logarithmic form, the decibel scale isn't going to be very useful for your purposes - the scale is designed to describe large differences in sound pressure over a narrow score range of 100 or 200. The softest thing you can hear is down by zero, and pain is at 150. That means most of the things you hear are all crammed into a narrow band of score.

End result: in terms of decibels, "person walking on stone" and "person walking on wood" aren't going to be very different. They'll just be "person walking on hard surface" - and then the answer really depends as much on the shoes as on the surface.

Folks are talking about contrast because, in terms of human hearing, contrasts often mean more than absolute dB. If you want to base on something real, dB isn't a very good measure.

 

[garrowolf]

But if I don't know what the levels are then how could I describe a contrast in the first place?

 

[Umbran]

But if I don't know what the levels are then how could I describe a contrast in the first place?

Because contrasts are not contrasts in level, but in character of sound. In a room that's filled with the quiet hum of office machines and air conditioning, the sudden sharp tap of a pen on a desk is not necessary any louder than the other noise, but it is of such different nature that it gets picked out of the background.

 

[garrowolf]

so what kind of game system are you advocating?

 

[Lidgar]

Because contrasts are not contrasts in level, but in character of sound. In a room that's filled with the quiet hum of office machines and air conditioning, the sudden sharp tap of a pen on a desk is not necessary any louder than the other noise, but it is of such different nature that it gets picked out of the background.

Umbran really nailed it above - and as stated previously, I don't think using an absolute db system is the right way to go - at least if you are trying to simulate how humans perceive sound.

A more "accurate" table would be to tie the DC to a percent or amount changed from the ambient. A very slight change (as noted in my post, 3 db or less) would have a very high DC, then you can scale it down.

Note that in a typical dungeon setting, there are likely many ambient noises that a character would become accustomed to - water dripping, rats and bats vocalizing, air movements, etc. In the wilderness it would become even noisier.

Detecting the "oddities" outside of these ambient sounds is the key.

 

[Janx]

Because contrasts are not contrasts in level, but in character of sound. In a room that's filled with the quiet hum of office machines and air conditioning, the sudden sharp tap of a pen on a desk is not necessary any louder than the other noise, but it is of such different nature that it gets picked out of the background.

welcome to the side effect of asking a question to design a game rule. Your whole concept is going to be challenged, because folks ARE taking more into consideration for their answer than just your base question.

That's not a bad thing, but as a designer, it is something you should expect to happen. Just roll with it. You'll hopefully get a better rule or get verification that your line of reasoning was sound.


Some of these question, probably the only way to get answers is to get a Db meter and try it out AFTER carefully reading how to take proper sound measurements. Sound volume decreases dramatically over distance. So when playing a gig with a band, and the house says sound can't be louder than 70 Db, you gotta ask "as measured from where?". Legally, sound ordinances tend to be "as measured from the side walk".

But then the ambient noise of the street may contaminate that reading, let alone if a car passes the officer taking the reading, right then.

And that's just discussing the difficulties of measuring Volume.

It's certainly not a bad concept to consider.
What is the volume of each activity, as measured in a quiet space.
What is the ambient volume of various places a party may find themselves in.

from there, the difference in levels MIGHT be a clue as to the probability of detection by a listener.

However, the nature of the sounds is also a factor as Umbran mentions. Carrying on a private conversation in a busy public place is possible because all the other people are making similar noises and NOT listening to anybody else. Whereas, talking in the woods, while an elven ranger waits along the trail, he's more likely to hear that as it approaches.

Walking in a dungeon wearing armor isn't horribly noisy, though somebody listening for an approaching intruder will hear it. Somebody who lives there and isn't on alert, may just think it's a different wandering monster, doing some wandering.

 

[garrowolf]

Okay I made some changes. Now you get a bonus to hear things if they are in contrast with the background noise.
I'm going to stick with the decibel scale though. Even if I removed it I would still end up with a chart that said this is louder or quieter then this other noise so it's the same thing.

Here is what I have:
ListenCheck - Nexus D20 Wiki

Tell me what you guys think!

 

[Olgar Shiverstone]

I think you can skip the decibel column on the chart, and just go with similarity. "If it sounds about as loud as ... use DC ...".