[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]

2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

File: 118 KB, 1200x959, 1200px-Active_Noise_Reduction.svg.png [View same] [iqdb] [saucenao] [google]

Anonymous Tue May 12 04:02:19 2020 No.11662820 [Reply] [Original]

Is there any way to record a specific sound, get an inverse wave of that sound and cancel that sound?

>>	Anonymous Tue May 12 04:06:21 2020 No.11662828 >>11662820 Yes. Take two speakers one in front of you and one behind you and just change the phase till you hear nothing

>>	Anonymous Tue May 12 04:08:56 2020 No.11662836 >>11662828 what if I wanted to cancel the noise from the air conditioner. Is there a software to record the air conditioner noise and make anti noise?

>>	Anonymous Tue May 12 04:10:11 2020 No.11662840 >>11662836 Wear noise canceling headphones it will do the job better then your hack.

>>	Anonymous Tue May 12 04:12:27 2020 No.11662846 >>11662840 Why?

>>	Anonymous Tue May 12 04:18:08 2020 No.11662859 >>11662820 yeah its called noise cancelling

>>	Anonymous Tue May 12 04:22:43 2020 No.11662867 >>11662836 why dont you just record the sound of your air conditioner and flip it using audacity

>>	Anonymous Tue May 12 04:24:08 2020 No.11662871 >>11662820 https://www.youtube.com/watch?v=tk1swhjARbk https://www.youtube.com/watch?v=ysNkjEnoRsU It's not sound, but the theory is pretty much identical in theory.

>>	Anonymous Tue May 12 04:28:54 2020 No.11662885 >>11662867 I've just recorded some sound on audacity and clicked on inverse and it sounded the same.

>>	Anonymous Tue May 12 04:30:19 2020 No.11662887 >>11662885 >I've just recorded some sound on audacity and clicked on inverse and it sounded the same. No shit, inverting it is just the same as adding a 90 Degree phase shift, doesn't mean it wont cancel lul

>>	Anonymous Tue May 12 04:49:49 2020 No.11662917 >>11662820 Yes. Considering you could google a suitable picture (or did you draw it tourself) you know that it does exist. So tell me, why are you asking?

Anonymous Tue May 12 04:52:50 2020 No.11662922

>>11662871
OP.
This is exactly what you need to understand what you're doing right here.
You need to produce waves that cancel out at 180degrees (so opposite waves).
Waves = sound.

i.e. if I have a positive peak of a wave that goes to +1, you would need a wave that goes to -1 to cancel out that wave.
Different instruments or sounds are at different frequencies, so you can cancel out a specific sound at a frequency if you know the negative inverse.

>>	Anonymous Tue May 12 04:59:43 2020 No.11662936 File: 19 KB, 1184x514, dongs.png [View same] [iqdb] [saucenao] [google] >>11662922

>>	Anonymous Tue May 12 05:00:52 2020 No.11662939 >>11662885 fucking idiot

Anonymous Tue May 12 05:29:29 2020 No.11663011

>>11662820
This is how noise cancelling headphones work, they have microphones that are on the outside of the headphones. Then, after the sound wave is picked up by the microphone but before it gets all the way to your eardrum, the headphones process the inverse and inject it into your audio at the perfect moment to try and have both waves enter your ear at the same time and cancel.

>>	Anonymous Tue May 12 07:27:55 2020 No.11663263 >>11663011 no, this is how high schoolers think they work and what their marketing hopes people will think too. here's a hint for you to try to figure out why what you've suggested won't work: noise in engineering does not mean the same thing as sound

>>	Anonymous Tue May 12 07:34:45 2020 No.11663283 >>11662828 Why can't this be done with jet engines? Have one engine produce the opposite sound to the second engine. Or any loud noise environment.

>>	Anonymous Tue May 12 07:35:29 2020 No.11663286 >>11662885 you have to put the speakers behind you, dum dum

>>	Anonymous Tue May 12 07:36:51 2020 No.11663290 >>11663283 It only works in a single spot since sound bounces and shit so it wouldn’t do anything

>>	Anonymous Tue May 12 08:18:52 2020 No.11663371 >>11663290 Ok, so why don't the airlines use a noise cancelling device within the cabin rather than me having to wear an irritating noise cancelling headphone?

>>	Anonymous Tue May 12 08:22:00 2020 No.11663375 >>11663290 If you cruising at 30 000 feet isn`t that like being in one spot anyway. Air is air wherever you are at that height.

>>	Anonymous Tue May 12 08:24:09 2020 No.11663378 >>11663375 Doesn't understand superposition

>>	Anonymous Tue May 12 08:39:49 2020 No.11663414 >>11662887 Phase shift isn't the same as inverting. A phase shift is more of a delay. If the wave is 100% symmetrical, a 180 degree horizontal phase shift will cancel it out. Otherwise an inversion and summation is needed for perfect cancellation.

>>	Anonymous Tue May 12 08:50:00 2020 No.11663440 >>11663414 Don't give him the answer ffs. He needs to work it out himself.

>>	Anonymous Tue May 12 09:24:10 2020 No.11663507 >>11662846 Because you're trying to reinvent the wheel, thats what noise canceling headphones do. They record sound coming in and use destructive interference to cancel the noise. You could also try a white noise generator.

>>	Anonymous Tue May 12 10:19:40 2020 No.11663652 >>11663371 The cabin is not a single spot. It's made of many different materials vibrating.

>>	Anonymous Tue May 12 12:03:25 2020 No.11664019 >>11663263 Idiot.

>>	Anonymous Tue May 12 12:51:48 2020 No.11664153 >>11662820 DAW's can do that easily. Even the most basic ones like Audacity

>>	Anonymous Tue May 12 12:53:37 2020 No.11664159 >>11662885 You need to have two channels with the same wave Select just one of them and reverse it. Otherwise you'd be just inverting, and cancelling the wave

>>	Anonymous Tue May 12 12:54:46 2020 No.11664162 >>11664159 *Not cancelling...

>>	Anonymous Tue May 12 19:21:34 2020 No.11665446 you just described active noise cancellation, which many headphones have, so yes, it is possible.

>>	Anonymous Tue May 12 19:27:37 2020 No.11665461 Do the air molecules literally collide? Can you cancel a water wave by generating an antiwave? Like from a tsunami?

>>	Anonymous Tue May 12 22:00:38 2020 No.11665880 >>11664019 wow good argument. look up the actual mechanism

>>	Anonymous Tue May 12 22:24:00 2020 No.11665937 >>11665880 https://en.wikipedia.org/wiki/Active_noise_control >wow good argument. look up the actual mechanism

Anonymous Tue May 12 23:20:14 2020 No.11666114

>>11663652
Also you want to make the plane itself as light as possible so you can pack as much onboard per flight as possible. A commercial plane is aluminum foil over a light skeleton so you can carry 30 more people. It's just easier to give people headphones and earplugs.

Anonymous Wed May 13 03:41:24 2020 No.11666727

>>11662820
>Is there any way to record a specific sound, get an inverse wave of that sound and cancel that sound?
Theoretically yes, practically, you can come pretty close to cancelling a sound from one speaking using another one at a specific point in space from both speakers.

>>	Anonymous Wed May 13 03:48:04 2020 No.11666738 >>11665461 >Do the air molecules literally collide? no really. usually you assume they don't interact with each other at all >cancel water wave sure

>>	Anonymous Wed May 13 04:38:34 2020 No.11666807 >>11665461 >Do the air molecules literally collide? yes >Can you cancel a water wave by generating an antiwave? Like from a tsunami? destructive interference works on pressure waves in water too, so yeah, in theory

>>	Anonymous Wed May 13 04:42:18 2020 No.11666813 https://en.wikipedia.org/wiki/Fourier_transform

>>	Anonymous Wed May 13 04:44:32 2020 No.11666822 >>11666807 >yes "no"

Anonymous Wed May 13 04:48:57 2020 No.11666826

if you did it realtime you would be limited on the buffer size and maybe it won't work
but in digital land you'd take a copy of your source buffer, reverse the ordering of the samples in the copy, then subtract the copy from the source buffer.
then output that result.

I don't think this will do what you want tho

Anonymous Wed May 13 12:21:42 2020 No.11667695

try to suspend the unit in the air away from solid surfaces and attachments and put pillows or something on any suitable faces without vents etc.
also break up your space with room dividers to change the shape and therefore the acoustic properties, if it is like a cube or double cube as these resonate more

Anonymous Wed May 13 12:27:15 2020 No.11667718

>>11662828
This is not going to work because of reflections in the room. If you want two speakers to cancel out, you would need a studio. Also, the two speakers need to be connected to the exact same source or else their frequencies might be off from one another.

>>	Anonymous Wed May 13 12:28:06 2020 No.11667722 File: 1.63 MB, 800x392, z8jg89jz.gif [View same] [iqdb] [saucenao] [google]

>>	Anonymous Wed May 13 12:38:58 2020 No.11667754 >>11667722 checked water be blessed

Advanced search
Text to find
Subject [?]Search by post subject. Leave empty for any.
Username [?]Search for user name. Leave empty for any user name.
Tripcode [?]Search for tripcode. Leave empty for any.
Email [?]Search by email. Leave empty for any.
Filename [?]Search by image filename. Leave empty for any.
From Date [?]Enter what date to start searching from. Format is YYYY-MM-DD
To Date [?]Enter what date to start searching until. Format is YYYY-MM-DD
Image hash
Search in	All Posts OPs Only
Deleted posts	Show all posts Show only deleted posts Only show non-deleted posts
Internal posts	Show all posts Show only internal posts Show only archived posts
Order	New posts first Old posts first
Capcode	All Posts Only by Users Only by Mods Only by Admins Only by Developers
Results	Posts Threads
Action	[ Simple ]