Thread: Nullifying sound

I remember hearing this at school, if you do something with a sound wave it cancels it out. Does this mean you could make an area completely sound proof.

...it's called interference, go do some research

Organic... don't flame.

Originally Posted by rjc79

I remember hearing this at school, if you do something with a sound wave it cancels it out. Does this mean you could make an area completely sound proof.

You can come close. That is the principle used to make noise-canceling head-phones. See Bose.

I think it can work okay for sinusoidal noise, not so much for transients.

Originally Posted by Harold14370

I think it can work okay for sinusoidal noise, not so much for transients.

Some of the electronics is amazingly quick and the systems can work pretty well for longer transients. It certainly works well for continuous noise that is approximately white (like airplane drone).

Originally Posted by rjc79

I remember hearing this at school, if you do something with a sound wave it cancels it out. Does this mean you could make an area completely sound proof.

I have found that high voltage, high speed blasts produce before the explosion occurs, a deafening. An eerie deafening.

There is certainly voltage present. And some strange gravity like effects. A deadness in the air. A silent stillness, that dampens sound. I would have to suspect high frequency.

I believe you could create a sound dampening field with high frequency, just outside the normal sound range. It might not be complete. However it might give you some surprising effects. By just creating multiple high frequency sources, all independent of one another.

After all, your ear is only one input device. That can only handle sound through the single device relaying it to your brain. So if it is vibrating at its ultimate input capabilities. It will definitely lose some of its ability to hear other sounds.

If the ear drum is quivering back and forth from high frequency inaudible sound. It can never receive and pass along a full precise description of a stronger sound. It will cut down on the power of normal sounds, getting through to the ear drum.


Sincerely,


William McCormick

Common-Emitter configuration of a BJT causes 180 degrees phase inversion.

This means absorbing the sound and inverting it by 180 degrees then releasing it.

When you add the real signal and the 180-degree inverted signal, the resulting signal is 0.

180 degrees can be represented by "pi". 180 means total opposite.
360 = 2 pi


This is one topic in Basic Electronics.

Try to look for images on phase inversion for better understanding.