The objective of this project is to create a software to measure the amplitudes of the harmonics present in a sound sample.
The strategy to accomplish that uses the fact that the first harmonic (fundamental) corresponds to the pitch of the sound sample, while the other harmonics (overtones) correspond to integer multiples of the first one.
The complete process is summarized in the steps below.
- Estimate the pitch of the sound sample, obtaining the fundamental and its amplitude;
- calculate the ideal frequencies for the overtones—integer multiples of the fundamental;
- analyze the power spectrum of the sound sample, and, for each ideal frequency calculated in (2), find the peak that is closest to that frequency;
- for each peak found in (3), obtain its actual frequency, and corresponding amplitude;
- return the amplitudes obtained in steps (1) and (4).
Resonometer will measure the amplitudes of the harmonics, which contain the natural frequency and its Fourier components, directly affected by resonance.
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of a periodically applied force (or a Fourier component of it) is equal or close to a natural frequency of the system on which it acts — Wikipedia