What is the audible level for digital audio dB units?

I was looking at a soundwave from an mp3 file. I am using the "Sonic Visualizer" app available on Linux. The amplitude is between ~ -0.1,0.1 in my file. I have already learned the amplitude is on [-1,1].

The soundwave is between ~ -40,-10 when I convert the soundwave to a dB y-scale. I have that dB conversion formula.

I read online that the human ear starts to hear near -10-10dB.

What does that 0-ish threshold correspond to in digital audio? Why are the dB reported in these audibility studies different from the dB I'm seeing everywhere in spectograms etc?

What is the audible level for digital audio dB units?

I was looking at a soundwave from an mp3 file. I am using the "Sonic Visualizer" app available on Linux. The amplitude is between ~ -0.1,0.1 in my file. I have already learned the amplitude is on [-1,1].

The soundwave is between ~ -40,-10 when I convert the soundwave to a dB y-scale. I have that dB conversion formula.

I read online that the human ear starts to hear near -10dB.

What does that 0-ish threshold correspond to in digital audio? Why are the dB reported in these audibility studies different from the dB I'm seeing everywhere in spectograms etc?