Passing planes and other whoosh sounds • Hacker News Board

Re: Passing planes and other whoosh sounds

#11

Post by beardyw » Thu, Apr 17, 2025, 8:35 AM UTC

normie3000 wrote: post #6

> it's like the pitch goes down at first, but when the plane has passed us, the pitch goes up again. That's not how Doppler works! Call me a dummy, but this was exactly how I thought Doppler works.

As a sound comes towards you (say an ambulance) the sound waves arrive squashed (higher pitch) and as it goes away the sound waves are stretched (lower pitch).

Re: Passing planes and other whoosh sounds

#12

Post by roygbiv2 » Thu, Apr 17, 2025, 8:36 AM UTC

We have planes pass overhead at about 6000ft. When the conditions are right they'll make a completely different sound, I've always assumed it's the Doppler effect mixed with the valley we live in but I'm always very curious when it does happen.

They make their usual sound but then there's a second sound that arrives, a lot higher pitched. Sounds like they've struck it in reverse or something (they haven't they're just doing a normal decent).

Re: Passing planes and other whoosh sounds

#13

Post by netsharc » Thu, Apr 17, 2025, 9:08 AM UTC

djmips wrote: post #9

maciejb wrote: post #4

Next time I see a plane coming, I’m going to lie on the floor to see if the whoosh sound does it fact change.

Check out his video. It's educational! https://www.youtube.com/watch?v=Amj4UevyRfU

She's a woman, btw.

Re: Passing planes and other whoosh sounds

#14

Post by ano-ther » Thu, Apr 17, 2025, 9:45 AM UTC

roygbiv2 wrote: post #12

We have planes pass overhead at about 6000ft. When the conditions are right they'll make a completely different sound, I've always assumed it's the Doppler effect mixed with the valley we live in but I'm always very curious when it does happen. They make their usual sound but then there's a second sound that arrives, a lot higher pitched. Sounds like they've struck it in reverse or something (they haven't they're jus…

Very interesting question. I thought that was when they extend their flaps so the wings become a bit wider for the slower flight and that creates some resonance.

Re: Passing planes and other whoosh sounds

#15

Post by oe » Thu, Apr 17, 2025, 9:51 AM UTC

roygbiv2 wrote: post #12

We have planes pass overhead at about 6000ft. When the conditions are right they'll make a completely different sound, I've always assumed it's the Doppler effect mixed with the valley we live in but I'm always very curious when it does happen. They make their usual sound but then there's a second sound that arrives, a lot higher pitched. Sounds like they've struck it in reverse or something (they haven't they're jus…

I think it’s some engine type that makes the sound at some specific speed / throttle setting. But I can’t remember the specifics. Some planes passing us make the sound, most don’t.

Re: Passing planes and other whoosh sounds

#16

Post by philipwhiuk » Thu, Apr 17, 2025, 10:09 AM UTC

roygbiv2 wrote: post #12

We have planes pass overhead at about 6000ft. When the conditions are right they'll make a completely different sound, I've always assumed it's the Doppler effect mixed with the valley we live in but I'm always very curious when it does happen. They make their usual sound but then there's a second sound that arrives, a lot higher pitched. Sounds like they've struck it in reverse or something (they haven't they're jus…

Sound is also reflected off a cloud layer if present.

Re: Passing planes and other whoosh sounds

#17

Post by smcameron » Thu, Apr 17, 2025, 11:17 AM UTC

Hm, I suppose that's why a flanger[1] (guitar effect pedal) can sound a little like a jet plane.

[1] https://en.wikipedia.org/wiki/Flanging

Re: Passing planes and other whoosh sounds

#18

Post by albert_e » Thu, Apr 17, 2025, 11:25 AM UTC

Tangentially related

I once picked up my memory foam mattress and stood it up against one of the walls ... for cleaning the bed or whatever.

As I walked past the mattress I instantly noticed that the mattress is such a good absorber of audio waves that I could immediately notice a dip in ambient sound in the ear facing the mattress.

The room was already "silent" and this newly discovered lower limit of silence was pretty surprising to me physiologically.

Re: Passing planes and other whoosh sounds

#19

Post by thefroh » Thu, Apr 17, 2025, 11:49 AM UTC

it's also the effect that lets you kinda know if you're near a wall (for example when you're fumbling around in the dark)

Re: Passing planes and other whoosh sounds

#20

Post by junon » Thu, Apr 17, 2025, 12:01 PM UTC

Pretty sure this is also why, when you stand at the right spot in a techno concert, the music starts to sound like a jet engine.

We also have this in game development, where if two sound effect emitters play the same effect at the same time with just a bit of offset, phase, whatever, they sound like that.