Is my voice recorded and played how people really hear how I talk/sing?

On iPhone voice memos?

Yes and no.

Yes, because now you are hearing your voice from outside your skull and WITHOUT any resonances from the bones of your skull.

On the other hand, small recording device like that have both BAD recording and BAD playback quality anyway, so the ONLY TRUE and HONEST feedback comes from a fully trained vocal teacher during an OFFLINE one-on-one audition (in terms of singing).

Not really. IPhone microphones have never been good at audio recording.

One way to at least have an idea how you sound to other is placing a flat object (a folder will do) in along adjacent to your sideburns and sing a note or speak.