Nope although it has that as an option as well. There are two options I use. The first is to boost the center channel on surround mixes since the voice is almost always on that channel.

Then more specifically in Kodi there is both a main volume option and a separate volume boot option that if you look into the documentation says that it is able to increase volume differently by moving up the middle of the audio while reducing the dynamic range. In other words reducing the difference between the lowest and highest sounds so it can increase it without clipping.

I basically change the main volume to what I want and then since both main and boost use the same numbers I reduce it by the exact same number I increase the boost level. End result is moving the bottom and middle of the audio volume closer.

In an ideal setup like a literal quiet audience in a full IMAX or with studio monitor grade headphones etc. the dynamic range is nice. Let's you hear talking normally and then get blown away by the action right at the top of the safe listening range. Or for classical orchestra music the quiet solot small instrument then a full booming with the entire band going.

But in reality I have five kids running around. Even in stuff like Pixar I still like having a fairly aggressive setting for the boost. It lets me set a default fairly aggressive one and then only occasionally need to edit it manually from the default for particular movies.