'Inner voice' as General purpose Intra-brain Communication Mechanism?

No time to write this up properly.... I wonder if one of the major reasons for our 'inner voice' is as a general purpose means by which information can be communicated between the various brain 'modules'?

It seems likely to me that the information 'vocalise' through our 'inner voice' is processed and filtered through to all parts of the brain that would normally receive information about the sounds (and thus speech) that we would hear through our ears. This would mean that if the brain can internally produce information and turn it into speech the 'inner voice' that all these areas of the brain can be informed of that.

Though I don't have time to try and think of what the reasons for this are, this seems more likely to me than always having all of these special purpose communication channels through the brain (perhaps it is because that might be duplication? Also, note that I'm not trying to deny the existence of special purpose communication channels).

I have heard that the 'inner voice' was likely to have been a later evolutionary development than the ability to hear and process language or language-like statements, and this intra-brain communication usage would thus have been one of the benefits it could have brought.

I don't know what might have been written about this idea already, and all I can say is that I have read a few things that I think ought to have mentioned such an idea if the author had been aware of it.