What Defines Noise in Scientific Terms?

[NoiseQuestion]

Hello everyone. I'm not a Physics major: I'm a Music major. And I have a question. I've read various books on acoustics, but I still haven't found the answer.

Ok. The way I see it, there are 2 basic types of sounds (I didn't get this out of a book, it's my own conclusion from everyday observation). One is pitch, the other is (for lack of a better word) noise.

Now every sound is a noise, right? True. But by pitch I mean a sound whose pitch we can determine. If I play a note on the piano, you can tell me "oh, that's a C", or you can give me some mathematical frequency for what we call "C".

By noise, I mean a sound whose pitch(es) cannot be determined. - And maybe I'm wrong about this, because I know next to nothing about Physics. But for example, say an airplane takes off and you have the unfortunate experience of standing behind it and you hear this EEEEEEEEEEEAAHHHHHHHHHHHH! or whatever. Now let's say you go to the piano and try to reproduce the "pitch(es)" of the engine going off. YOU CAN'T! Because the sound has no pitch we can determine. It's just noise.

Now here's my question. 1) Is everything I said above true? and 2) If it is, how do we describe, in scientific terms, what I have termed "noise?" If it has no defined pitch, what is it? What is the technical term for it, and how can we analyze it?

Thank you for your time!

 

[jim mcnamara]

Your definition of noise needs help. By your definition, human speech would be noise because it cannot be reproduced exactly on a musical instrument.

You probably need to read to read a short blurb on
noise
technical definition
http://www.pcmag.com/encyclopedia_term/0,2542,t=Gaussian+noise&i=43682,00.asp

http://www.its.bldrdoc.gov/fs-1037/dir-024/_3556.htm

white noise
http://en.wikipedia.org/wiki/White_noise

brown noise
http://www.mediacollege.com/audio/noise/brown-noise.html

1. Answer no.
2. You cannot your; definition of noise seems to have problems.

 

[Blueshift5]

Hello there, as a scientist, I would be happy to provide some insight on your question about noise vs. music. Firstly, I want to commend you for your observation skills and for seeking out answers to your question through books and now through reaching out to the scientific community.

To answer your first question, yes, everything you have said about pitch and noise is true. Pitch is a subjective perception of sound that can be determined by the frequency of the sound waves, while noise is a sound that does not have a discernible pitch.

Now, let's dive into the scientific explanation of noise. In physics, noise is defined as any unwanted or random fluctuations in a signal. This can include sounds that are not easily distinguishable or have no discernible pattern. In fact, noise can be present in all aspects of our lives, from the hum of a refrigerator to the sound of traffic outside.

In terms of analyzing and describing noise, there are various scientific techniques and tools that can be used. One common method is through spectral analysis, where the frequency and amplitude of a sound can be measured and visualized. This can help identify any patterns or frequencies present in the noise. Another method is through statistical analysis, where the randomness and distribution of the noise can be studied.

I hope this helps answer your question and sheds some light on the scientific understanding of noise. Keep asking questions and exploring the world around you, as that is the essence of science. Best of luck in your studies!