A few weeks ago, I flew into PDX and rented a car at National's remote lot. I forgot to set up my GPS untill after I left the lot, and later found the perfect place to pull over and set it up: under the approach path to one of the runways.
I've never done any plane spotting, and so never been able to observe planes this close to the ground on their final approach. I've read, however, that wake turbulence can make funny noises under the approach path.
I watched a 767 fly overhead as I was trying to program the GPS. About a minute or two later, I was startled by a sound that seemed to be coming from everywhere.
It was as if someone was plucking a giant wood saw, or maybe long suspension bridge cables breaking. Come to think of it, it was exactly like the sound effects in Dr. No when Sean Connery is crawling through water pipes after escaping from his prison cell in Dr. No's lair.
A lot of setup for a simple question: is this what wake turbulence sounds like when it descends to the ground under an approach path?