Thread: I need a way to block Ultrasound Frequencies between 19-800kHz, as well as radio frequencies via helmet?

Any ideas? What materials?? Do I need an entire suit like Iron Man to ensure it is grounded? If a motorcycle helmet creates a vacuum with ventilation vents then do I have t run around with it on, and should it be coated in lead or nickel?

Originally Posted by mcriv880

Any ideas? What materials?? Do I need an entire suit like Iron Man to ensure it is grounded? If a motorcycle helmet creates a vacuum with ventilation vents then do I have t run around with it on, and should it be coated in lead or nickel?

How many times, in how many ways, are you going to spam this forum with this question?

If you are worried that you are being bombarded with ultrasound, the first step would be to verify whether that is actually true (hint: It isn't). You are skipping an important step.

Bro a few FBI Agents told me it was 100 percent true and directed me to papers on the tech.

Time for the trash.

I need a way to block Ultrasound Frequencies

We need a way to block you from starting another one of these goofy threads. Please stop.

Originally Posted by mcriv880

Any ideas? What materials?? Do I need an entire suit like Iron Man to ensure it is grounded? If a motorcycle helmet creates a vacuum with ventilation vents then do I have t run around with it on, and should it be coated in lead or nickel?

It needs to be solid lead, at least four inches thick to provide true protection. Anything else and you will be vulnerable to all sorts of hair-destroying and mind-controlling rays.

Originally Posted by mcriv880

If a motorcycle helmet creates a vacuum with ventilation vents then . . . .

I really don't want to ask this but . . . but . . . but what gave you the idea that a m/c helmet creates a vacuum? (I dread the answer but I'm like a moth lured to a flame . . . )

I don't think we should dump this thread because it has somewhat to do with physics even though it may seem out of the ordinary.


First I would say usually lead is just bad around humans. Yes there are safe ways of using lead, but if you don't have to then I would say don't do it just for the health risks.

I would say the lead would probably kill you before the ultra sound.


I have several motorcycle helmets there is not a single place in the helmet that is a vacuum. It's a hard shell with soft padding in the middle that is very easily air and water permeable.

Originally Posted by ScienceNoob

First I would say usually lead is just bad around humans. Yes there are safe ways of using lead, but if you don't have to then I would say don't do it just for the health risks. I would say the lead would probably kill you before the ultra sound.

Plate it with gold. Gold is completely nonreactive and safe for contact with human skin.

I have several motorcycle helmets there is not a single place in the helmet that is a vacuum.

If you had a full face helmet with a good neck seal you could pull at least a weak vacuum inside.

What the OP needs to do is coat their bathtub with "Pam" no-stick spray, fill it full of water and add like 25 packages of "jello"....then get in and completely submerge themselves. You'll need a straw to breath. Then when the jello sets...just walk around with your new infrasound proof jello suit. Avoid ant beds at all costs.

Originally Posted by Chucknorium

Originally Posted by mcriv880

If a motorcycle helmet creates a vacuum with ventilation vents then . . . .

I really don't want to ask this but . . . but . . . but what gave you the idea that a m/c helmet creates a vacuum? (I dread the answer but I'm like a moth lured to a flame . . . )

It's listed as a vacuum helmet while riding depending on the vent shape and placement I think. Correct me if you think I'm wrong though.

Originally Posted by mcriv880

It's listed as a vacuum helmet while riding depending on the vent shape and placement I think. Correct me if you think I'm wrong though.

A full-face helmet does not have an air-tight seal for the flip-up visor, there is no air-tight seal at the neck, and the venting is to cool the head in the summer and keep the visor from fogging up in the winter. The vents have intakes, usually just under the visor by the chin and the air is vented out the top, usually. The more expensive the helmet, the better the venting. Not airtight by any measure. Even with the vents closed, it is not air-tight.

Ultrasound?
The best medium for absorbing it is likely water since water has an attenuation factor of about 2 at those frequencies.
However there is such a thing as acoustic impedance. With sound passing through two different materials with different acoustic impedance values a portion of the sound wave cane be reflected. How much is reflected depends on how closely the impedances match or differ.
The effect is very similar to impedence in electronics.
Water has a high impedance value while air has a faily low impedance value. A helmet with a hard shell, water pouch lining, plus an air space should reflect most of the ultrasound.
For the radio waves you could try to reflect them too. You helmet should be metalic on the outside and be about 1/2 the wavelength of the radio waves.
You could also get a radio tech to design your helmet with an antenna and circuitry that would essentially act as a power recieving antenna. Wire it up to a small fan or some blinking lights and not only would you have a breeze to cool your head inside the helmet, you would have a set of turn signals too.

Originally Posted by dan hunter

Ultrasound?
The best medium for absorbing it is likely water since water has an attenuation factor of about 2 at those frequencies.
However there is such a thing as acoustic impedance. With sound passing through two different materials with different acoustic impedance values a portion of the sound wave cane be reflected. How much is reflected depends on how closely the impedances match or differ.
The effect is very similar to impedence in electronics.
Water has a high impedance value while air has a faily low impedance value. A helmet with a hard shell, water pouch lining, plus an air space should reflect most of the ultrasound.
For the radio waves you could try to reflect them too. You helmet should be metalic on the outside and be about 1/2 the wavelength of the radio waves.
You could also get a radio tech to design your helmet with an antenna and circuitry that would essentially act as a power recieving antenna. Wire it up to a small fan or some blinking lights and not only would you have a breeze to cool your head inside the helmet, you would have a set of turn signals too.

Great explanation also the helmet idea seems to be very effective as well for solving this problem

take some copper screen and wrap it around your head, mix a 5 gl bucket of concrete stick your head in it till it sets up
let us know how it works.