Doing some more experiments I was jumping in ffmeg codebase

In file aacpsy.c there are three include

#include "avcodec.h"
#include "aactab.h"
#include "psymodel.h"

And all of the three headers are in the same directory.
now "aactab.h" is not found, I can't jump to it and even bovinate
doesn't say anything about it.
What is the different between the other two I don't get it??