Our Gemara on Amud Aleph suggests that though ordinarily we say that one cannot hear two voices at the same time, when the sounds or subject matter are dear to the listener, apparently one can maintain focus and hear the distinct sounds.  Thus, with regard to the reading of Hallel and the Scroll of Esther, even ten people may read simultaneously.  

This idea strikes me as important in human relations and even in relation to ourselves.  In our families there may be many voices and opinions, and truly even within our “internal family” in our head, we might have differing needs, ideas, and convictions.  While ordinarily it is impossible to hear two things at once, it would seem if the subject matter is seen as special and beloved, it is indeed possible. When we learn to respect and listen carefully to what is going on inside our heads, as well as being actively interested in what others whom we love have to say, we can be truly attentive.

Notably, Rashi here says an added point as to why the subject matter of the Megillah or Hallel are dear to the person, so that he can discern the various voices reading simultaneously: “Because it is new material”. Presumably, Rashi is saying that since these are occasional rituals, the subject matter feels new and interesting.  This is an important clue as to how to hear others, especially multiple opinions or views within a family. If we are humble and curious, and understand that each person may have a new and fascinating point to make or nuance to add, then we can listen attentively to many voices at the same time.