Sound wave -- positive and negative frequency?

[btb4198]

does ever sound wave have a positive and negative frequency?

 

[berkeman]

does ever sound wave have a positive and negative frequency?

Sure. Are you familiar with the Fourier transform?

 

[btb4198]

Sure. Are you familiar with the Fourier transform?

yes, I am. why do you ask ?

 

[berkeman]

yes, I am. why do you ask ?

Because when you take the Fourier transform of a sine wave, you get a spectrum plot like this:

http://fweb.wallawalla.edu/class-wiki/upload/f/fa/Hw12b.jpg

 

[btb4198]

I know it is right for a sinwave, or you saying it is the same for sound wave? like someone talking or singing?

 

[berkeman]

I know it is right for a sinwave, or you saying it is the same for sound wave? like someone talking or singing?

Yes, I believe so. It's mainly a mathematical artifact of the way the FT is calculated. Do you have some particular thing in mind?

http://www.gaussianwaves.com/gaussi...-domain-how-to-plot-square-wave-in-Matlab.png