# The exact definition of dominant frequency?

What is the exact definition of dominant frequency? I have googled and cannot find it.

For example, does this figure shows "two" dominant frequencies? Is dominant frequency a single maximum value? or do we call it dominant frequency because it has a distinguishable peak observed by human?

Edit: another example,

• Where did you hear the term "dominant frequency"? Commented Apr 12, 2017 at 14:39
• @endolith hi, I have added the context in the question
– zlin
Commented Apr 12, 2017 at 15:15
• Aha. So it's just the largest frequency component. See en.wikipedia.org/wiki/Missing_fundamental Commented Apr 12, 2017 at 16:02

As dominant frequency it is usually meant the one that carries more energy w.r.t. all the other frequencies in the considered spectrum.

Since in the first example the two frequencies have the same absolute value I suppose they are both dominant frequencies. However the concept is not really important in these case, since you are just looking at the combination of two pure sinusoids of equal amplitude.

In the second case, the lowest frequency is both the fundamental and the DOMINANT frequency since it has the highest peak of the considered spectrum.

Reference: https://arxiv.org/pdf/1306.0103.pdf

• So in other words, dominant frequency is strictly defined as the frequency with the largest amplitude on a spectrum.
– zlin
Commented Apr 12, 2017 at 15:22
• Yes, exactly! It is a definition usually employed when working with musical content as I suppose you are doing
– Luca
Commented Apr 12, 2017 at 15:26
• hi, do you think "main frequency" is just the same as "dominant frequency"?
– zlin
Commented Apr 13, 2017 at 14:55
• probably yes, however I am not sure since I do not know if there is an exact definition for main frequency! Can you provide some context?
– Luca
Commented Apr 13, 2017 at 21:19