i can confirm through my faith.
an example is once i was walking down an upper path at the beach, a pinecone fell in front of me glowing brilliantly like the sun.
the feeling i got from witnessing this was unearthly. i know 100% it was a vision from The Holy Spirit.
i've had other visions, some would think hallucinations. for example, everything turning black and white, and a modern car turning into a model T right before my eyes.
as far as the audio, when listening to people speak, certain words or phrases "zap" me into a religious state of mind instantly.
as if a third party jumped into the conversation. without faith, i would think i needed my head checked.