About Whisper
It is an application which can tune volume finely.
Fine tuning between the volume 0-1 can be performed.
Controllable in a notification.
Limitations
-It cannot use simultaneously with an equalizer.
-There is an effect in music playback, YouTube, etc.
But may be ineffective.
Please check by a free test version.
If the trial version was used, please be sure to delete the trial version.