i heard a strange throbbing humming sound that made me freeze until it passed.

I believe this happened when i was about 6 years old...it may have been later or earlier than that. I truely do not remember...in fact I barely remember this experience.
I was out in my grandmother's yard (she owned an acre of land at the time) and as i was playing i froze. there was a paralyzing sound all around me. It was like a throbbing hum and it felt like it was rubbing against my eardrums. I didn't move, all i could hear was the this one noise. I really don't know how to describe it, it was as if i were caught in a wall of sound. the noise soon passed and everything was back to normal. I told some of my family later on but no one really believed me.
In wilmington illinois where this happened, there is an old army arsonal. I have no idea what happened that day.