I still don't "buy" that some people don't have an inner voice. In my opinion it's either a misunderstanding of what it means to have an inner voice (it's not the schizophrenic "other person" voice), or people simply lying to appear quirky and special.
If people don't have an inner voice, it also must be the case the some people (these people?) don't have consciousness. It isn't obvious that consciousness is essential to fitness, especially of an inner voice isn't. Some people may be operating as automatons.
The obvious error here is that an inner voice is not fundamental, and the fact that many people describe their consciousness in such different terms makes it much more likely that consciousness is just something that manifests in a variety of subjective experiences.
If people don't have an inner voice, it also must be the case the some people (these people?) don't have consciousness. It isn't obvious that consciousness is essential to fitness, especially of an inner voice isn't. Some people may be operating as automatons.