I may regret having tied "sex" to this, but I can't help thinking that one of the body's prime instruments - the voice - would have some sort of testosterone/pheromone related "attractant" attribute - and perhaps goes through changes (both in delivery and reception ??) through the stages of being a juvenile to an adult to a geezer.

As I re-read the above, I'm reminded of the voice breaking ritual that some males go through at about the age of 13 - 14 !