How to correctly formulate the requirements for the volume of an audio file?

Question

Audio

Hey!
We are using ffmpeg to create a series of video tutorials (audio + video). We want to establish uniform requirements for the sound track in terms of sound level.
How can I set the volume requirements for audio files - in dB or other units? Our goal is to write a "validator" and run all incoming audio files through it to make sure that all our video lessons have the same volume level.

Answer 1

0db?

Answer 2

Loudness actually comes from dynamic range - the ratio between the highest peak in the file (0 dB) and the RMS value of the entire track (-N dB). The smaller N, the louder, but the quality is lower. For quality symphonic music N>10. If there are no specific requirements, then N~3 will do for normal speech.