How can I measure the harmonicity of an audio spectrum?

1. How do you check harmonics on a spectrum analyzer?
2. How do you calculate harmonic noise ratio?

How do you check harmonics on a spectrum analyzer?

Harmonic distortion may be measured by looking at the output spectrum on a spectrum analyzer and observing the values of the second, third, fourth, etc., harmonics with respect to the amplitude of the fundamental signal. The value is usually expressed as a ratio in %, ppm, dB, or dBc.

How do you calculate harmonic noise ratio?

A Harmonicity object represents the degree of acoustic periodicity, also called Harmonics-to-Noise Ratio (HNR). Harmonicity is expressed in dB: if 99% of the energy of the signal is in the periodic part, and 1% is noise, the HNR is 10*log10(99/1) = 20 dB.