Musical ‘notes’ are composed of fundamental tones and harmonics. It’s the harmonics that allow you to distinguish between several instruments. By integrating the fundamental and harmonic tones, we recognize the notes from the musical instruments and the ones sung by a vocalist.
As we all know, the human ear is more sensitive to certain octaves in the musical spectrum than to others. The spectrum where speech and voice communication occurs is called the midrange frequencies. And the human ear is tuned more towards this frequency range. Therefore, a very small energy changes in the midrange frequencies cause much more noticeable effects than larger changes in the very low and/or very high-frequency ranges.
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