Is a jammer effective against Ultrasound? Or do you need to use a White Noise Generator?

I think the book states that Ultrasound is more succeptable (spelling?) to jamming than normal, but it gives no rules. I'd say reduce the Sensor of Ultrasound by 2 or 4 for Jamming. A white noise generator simply masks your words and prevents people from listening in unless they beat your Generator's rating - it's the same but different.

Speaking of jamming, I think the jamming rules are awful as-is. At my table, Jammers reduce the rating of all Signals in their effect by their rating, but otherwise follow the rules of jamming (reduced reduction the further away from epicenter you are), and if a signal is reduced to 0 it can't broadcast.

Why in the world would ultrasound (that utilizes sound) be affected at all by a jammer (that utilizes electromagnetic noise)?

That's like clapping my hands should mess up someone's vision.

Hey, it worked in How To Train Your Dragon.

Oh? I kind of wanted to see that but never got around to it. May have to put it on my netflix list next time I want something funny.

No, you can't jam ultrasound, unless you had some nifty ultrasound jammer.

That would be a dog whistle, right?

Ultra-Wide Band Radar can be jammed, so I guess the difference is sound waves vs radio signals? I thought difference between sound and radio signals was frequency of waves (higher for radio vs ultrasound), so thought maybe jammer with wide enough frequency range would work.

What is the range for Ultrasound?

Yes, UWBR uses radio waves. Sound waves and electromagnetic waves aren't even... well, okay, they're vaguely similar in that they are both waves and have frequencies and such, but they are different in a very important way: Sound waves are the vibration of molecules (usually air) and electromagnetic waves are the movement of photons. Thats ultra basic to the point of being slightly wrong, but it gets the point across.

Is there any reason you couldn't use an ultrasound sensor of your own to jam-on-the-fly with?

As a sensor, it DOES have a Signal.

Same reason that two bats can fly together I'm guessing. They'd be designed to put out slightly different frequencies so as to specifically not mess each other up. That said, I'm sure that you certainly could make a jammer for ultrasound, or even modify your own to mess with someone else's, but I don't think that it'd be a standard feature (if only because it isn't mentioned).

Edit: Actually that isn't completely right about how bats do it, they actually do a particular pattern in their ultrasound bursts, so they'll be able to tell if something is their own or from another bat. They can be tricked though, but it is very difficult. Depending on how ultrasound goggles operate, it could actually be very difficult to trick them. The trick for bats has to be individualized to the bat's clicks. Then again, have your jammer pick up on that pattern, and then fire out random noise in that pattern and you could mess someone up fairly well.

There actually isn't any reason you couldn't 'jam' ultrasound. It is sound waves, with the right instrumentation and generators you can destructively interfere with it to the point of having little to nothing perceived. Or you could, as previously noted, white noise it and fill the entire area with too much ultrasound for the instruments to differentiate. There are a couple of other methods to do it technologically but the last way you could try it is to just.

Silence.

And poof. Ultrasound magically jammed.

That's the opposite of jamming, but sure.

Basically, the game doesn't have sound jammers, and we *know* it's stupid to allow radio jamming to in any way interact with sound… so you're left without sound jamming. Oh well. There *are* counters, or you can invent the sonic jammer. It'd work just like the radio ones, basically.

HE grenades make the best ultrasonic jammers. Machine guns on cyclic are next best.

I may have been thinking of Radar.