Very quiet planes

[Red]

I just had a demonstration of how quiet planes have become in order to comply with the FAA stage 4 noise requirements. I saw two planes come in for landing last night and was completely floored at how quiet they were. I did a quick internet search and determined that the planes were CRJ900s from Delta.
I checked mapquest and I am roughly 3 miles from our airport (I was thinking I was 5-7 miles away). The first CRJ900 that landed 6:30 pm I couldn't hear at all. The second one came in around 11 pm and the residential area that I live in was very quiet. I had to strain to hear its engines and it was at least an inch long in my field of vision.
A quick internet search revealed that CRJ class airplanes exceed stage 4 noise requirements.
Why do I think this relevant? Because a low noise or lack of noise in current or future sightings may not denote a craft of extra dimensional or inter-dimensional origins.

 

[Xylo]

Man I wish those planes were landing at Dulles Airport...In the last year they've had louder and louder planes landing.

 

[Jay]

Have you heard any of them taking off? I wonder if they're noticeably quieter then.

 

[Red]

No, but where they take off is a little bit further from my house. If I lived south or west of the airport, I might be more aware of the noise.
Edit: I do have to say that I have notice that I don't hear the traffic like we used to and we have lived here since 2002. My mouth was hanging open when I saw that second plane come down and I could barely hear it. I can still tell when the fighter jets are taking off/landing and they do love to use their afterburners.

 

[Red]

Have you heard any of them taking off? I wonder if they're noticeably quieter then.

I happened to catch one that was taking off last night. I could hear it, but it only got really loud for about 10 seconds when it was gaining altitude, which it did very quickly.