From what I can tell, if you don't have imagery, you don't have audio. If you happen to be someone who can hear audio internally (audio hallucinations) yet don't form imagery internally (historic iconic memories, faces, shapes, creative viz, etc.) hit me up on email.
Hams and hunters are the only people I can think of in modern life who listen very closely to silence, or noise anyway.
The trick will be finding one with Aphantasia, given my "proof" requires looking for someone who doesn't visualize AT ALL, yet still hears regular audio hallucinations.
There's a somewhat controversial book called The Origins of Consciousness and the Breakdown of the Bicameral Mind which seems to indicate audio hallucinations were quite common in earlier periods.
I'm not in the habit of "talking" to myself as many people seem to, the soundtrack of my mind can easily be silent. But if I want to rehearse what I want to say or something I can imagine it clearly.