Add to that Peter that remembering a person's voice such that you can recognize them consistently occurs beyond a single minute of listening. The brain needs time to be able to recall who's voice belongs to who through multiple listening sessions and exposures to the constant sound, and even then, the individual's perception of their voice changes over time.
I once met a guy at our building the first year i was there. His voice was high pitched, almost like he had not spent enough time going through puberty. This stood out as being odd and I kept mistaking him for a woman when i heard him in the halls. Now i can recognize his voice easily, but i no longer find it to be high pitched at all. His voice sounds like anyone else's (blends in to my ears) with no pitch abnormality, yet based on what i remember from my first impressions, his voice is abnormally high pitched for the average man.
My brain has 'broken in' the hearing the tone of his voice although i cannot exactly recall when i no longer perceived him as having a high pitched voice. It just happened.
