The spell's description reads:
"Creatures in the area who can see the denounced creature must make a Will Saving Throw or have their starting attitude toward the denounced creature worsened by two levels (see page 94 of the Core Rulebook). For example, creatures previously indifferent to the subject turn unfriendly."
However, two levels would mean indifferent becomes hostile, not unfriendly.
Either the amount of attitude adjustment is wrong, or the example is wrong. Which is it?
For a 4th level spell I expect the 2 levels is the correct change. So indifferent to hostile. But no way to know for sure without tracking down the original auther of the spell.