I thought about this. IIRC a person's voice sounds deeper in his own head because it reverberates in his skull. if anything, this would make David think the NotebookLM voice sound less like his (since his is already deeper, to begin with). But it's possible that a professional radio host is aware of this effect and adjusts for it when deciding if something sounds like him. Maybe he over-adjusts and thinks this is what he sounds like.
As for his wife, it's possible that he speaks in a higher/friendlier register when talking to her/their kids.
alt Hacker News
I thought about this. IIRC a person's voice sounds deeper in his own head because it reverberates in his skull. if anything, this would make David think the NotebookLM voice sound less like his (since his is already deeper, to begin with). But it's possible that a professional radio host is aware of this effect and adjusts for it when deciding if something sounds like him. Maybe he over-adjusts and thinks this is what he sounds like.
As for his wife, it's possible that he speaks in a higher/friendlier register when talking to her/their kids.