We can measure the degree of resonance of sound (voice, musical instruments) with human organisms.

Interestingly, real Stradivari violins have a very high degree of resonance, about 70%, a level of pleasantness.
Usually professional singers have a high degree of pleasantness in their voice. For example, Alla Pugacheva has 65% pleasant voice. Nikolai Baskov has about 55%. Elton John -55%. Freddie Mercury 50%.

QUESTION: What are the meanings of a pleasant and unpleasant voice.
ANSWER:
People perceive the voice as pleasant if its resonance with the body is above 40%.
Below 20%, the voice is perceived by people as unpleasant.
The voice is perceived as pleasant from the level of 40%
(people begin to understand, emphasize that it is pleasant).
20-40% - average voice parameters.

These parameters are tested in the personality energy chart.

FEEDBACK: Adjust the pleasantness of the voice.
I noticed that I began to like my voice more, when I speak, I began to listen to myself and noticed that the sound flows more smoothly and the voice is less interrupted.
/ Note: adjusted the voice from 30% to 50% / FEEDBACK: Adjust the pleasantness of the voice.

After adjusting, I was told that the voice became more pleasant.
Gone are the harsh notes in the voice.