Sound wave -- positive and negative frequency?

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Discussion Overview

The discussion centers around the concept of positive and negative frequencies in sound waves, exploring the relationship between sound waves and Fourier transforms. Participants inquire about the applicability of these concepts to various types of sound, including speech and singing.

Discussion Character

  • Exploratory
  • Technical explanation

Main Points Raised

  • Some participants inquire whether all sound waves possess positive and negative frequencies.
  • One participant references the Fourier transform as a basis for understanding the frequency spectrum of sound waves.
  • There is a suggestion that the behavior observed in sine waves regarding frequency may also apply to more complex sound waves, such as those produced by speech or singing.
  • Another participant mentions that the presence of positive and negative frequencies is primarily a mathematical artifact related to the Fourier transform.

Areas of Agreement / Disagreement

Participants express curiosity about the relationship between sound waves and Fourier transforms, but there is no consensus on the implications of positive and negative frequencies for different types of sound.

Contextual Notes

Participants do not clarify the specific conditions under which the concepts of positive and negative frequencies apply to sound waves, nor do they address potential limitations of the Fourier transform in this context.

btb4198
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does ever sound wave have a positive and negative frequency?
 
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btb4198 said:
does ever sound wave have a positive and negative frequency?
Sure. Are you familiar with the Fourier transform?
 
berkeman said:
Sure. Are you familiar with the Fourier transform?
yes, I am. why do you ask ?
 
btb4198 said:
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
Hw12b.jpg
 
I know it is right for a sinwave, or you saying it is the same for sound wave? like someone talking or singing?
 

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