With how much people hate the sound of their own voices, I think that would backfire on the advertiser.
Subvocalisation. Your own voice speaking quietly in the background to something else. Ideal for consumer indoctrination.
The voice we hear in our head and the one everyone else hear is starkly different.
The voice I 'hear' in my head and the one I actually hear when talking is starkly different.
So, ads spoken with your voice, as you would hear it from your head.
It they could make it sound like my voice sounds from inside my head, and not like the weirdo that other people apparently hear, it would be scary on several levels.