Teresa of Avila very unambiguously reported hearing voices. She's a saint. John Forbes Nash heard voices. He won a Nobel prize. Robert Schumann heard voices that spurred him to write great music.
Philip K. Dick was guided by one inner voice, specifically female, that he would hear for much of his life. He probably holds the record for most film adaptations for words written of any author ever.
Mahatma Gandhi described a voice he could hear; not a metaphorical inner conversation, but a voice.
I could go on. Hearing voices is not that unusual.