So yeah, it took me a little while to get this last one up finally, but here it is! I'll have two more in the "AwakeningFest" series coming this week, so do stay tuned. After that, I have another sound project set from a sheep festival (weird, huh)!
I think the security guard who helped me get these said it best. "It's that instant reaction," Kate C. said, and went on to explain that the interest in the question comes for her from seeing people's momentary reaction. An alarm, a siren--these are things that people instantly react to, things that stir people's blood and let them know danger stalks, or awaits in a business suit, or approaches in the form of a missed school-bus. These sounds become the Most Important Sound because we instinctually respond, and because they save our lives.
The instant, spur-of-the-moment hypothesis Kate offered also fits nicely with the other answers. To musicians, music is like your alarm. It's the thing that keeps you alive. It's the sound that protects you, or with which you warn the world. I think, anyway. Not being much of a musician myself, I'm not sure I know. The sound of the wind follows nicely from music, because it's a sound that culturally we associate with music and poetry. If Kate's theory is correct, the first answer, aside from being funny, highlights what pops out into Zach's head when he hears "important"--his wife. (cue d'aaaaaaawww)
So if you had to go on a gunshot gut reaction, what do you think when you hear "important"? How would that change your MIP answer?