MatPat: “Sound travels faster and is louder at night” Me dropping a cup at night: “Yes”

as a musician, I can say this: grab two mics and two amps, plugging one mic into each, then take a dog whistle or helmsman's whistle, piccolo etc. and play it into one of the mics, quickly making sure they are picking up everything from each other's amp. This will literally create a theoretically infinite loop of gradually louder volume and pitch if the amps have... well, amplifiers in them. So no average speaker would be okay, you must have an amp. Theoretically, because at a certain point your ears just wouldn't hear it or would be too damaged to hear it. Bring ear mufflers probably.

this helped me in science class, thanks for explaining sounds

Can you imagine being chased by a monster and fall to the ground before looking up to see a whole group of rock players as someone starts shredding an electric guitar and the lead singer starts singing a whistle note. Meanwhile the monsters start to writhe in pain and another person shoots it in the head

Fun fact: in the beginning of a quiet place 1, you can see that the chips aisle was completely full because people were too afraid to eat chips cuz they make sounds. Can't belive the directors went into such detail

Heyyy! Thanks for using our Distance Attenuation calculator at 5:08 :) We have a lot more calculators like that if others want to check it out :D

I grew up in a pretty toxic environment and I learned to be so quiet. I just wanted people to forget I was home. I would walk differently. (I would take slow steps and bend my knee when I planted my foot.) I would even breathe differently. (would sort of open my mouth halfway and flatten my tongue.) If I weren't so clumsy, I'd be so good at living in this hellscape!

Me if the Angels of Death, Weeping Angels, and the invisible ghosts come to Earth: ok bro, we're actually screwed this time.

When I was a kid, sometimes I’d wake up on a cold morning and tell my family “It sounds cold outside” and they always thought I was making things up. Cool to know that cold air actually does affect sound, so little me probably could tell it was cold from how it sounded!

What's crazy about this video, is how MatPat virtually figured out how to beat the Death Angels just by using TRshow videos that play at 1400-1900 Hz. The most dangerous weapon is a smart mind.

yes, sound does travel faster at night. sound is just particles vibrating, and when a particle vibrates it usually bumps into nearby ones and causes it to vibrate as well. so during the day, when it is warm the particles in the air will be less dense and therefore farther away from each other which means that the particles will not bump into others as quickly as they would in cold air (cold air is more dense, the particles are closer together and has the opposite reaction to warmer air). idk if that makes any sense but I explained it best I could

The fact that in that movies canon no one including the military thought to set up a mine field with a wireless sound system broadcasting in the center or simple spike pit traps with a noise maker at the bottom after everyone realized the creatures react and hunt to sound is amazing to me

Anyone wondering in music terms, 1500 sounds around an F, and 1900 sounds around a Bb. I believe higher pitches would also work, because since they have supersonic hearing they can probably hear higher frequencies than humans too. Because they have far superior hearing, u could probably play a pitch too high for us to hear and get that reaction from the creatures.

I’m curious as to how the death angels might react to a harmonic scrape on a cymbal. It’s definitely more similar to the implant’s feedback than say a 1500Hz sine wave, but I’m not sure what size cymbal you would need to generate the desired frequency, or if any would do.

MatPat is just like that teacher who says: “We still got a minute” and then explains the lore of everything in said minute.

I enjoyed the movie, but I still question why the death angels react to basically the volume of sound, and not specific sounds themselves. They must all suffer from ADD. A primary requirement of hunting by sound be knowing which sounds are important; given that these creatures are entirely alien to Earth, how do they have any reference regarding what sound is important and what isn't? Perhaps it can be explained, but this struck me as a big nope to me. Additionally, as other commenters have pointed out, sound can easily be used as a tactic against the monsters. Saturating an area with sound to mask movement and even gunfire--artillery shelling to create saturation that would completely overwhelm their auditory capabilities. You don't need to know a specific frequency, you just need to know how to smartly exploit their own advantages. Sort of why I don't understand why zombie movies, because fire is a thing, and zombies are very stupid. lol

I thought that the aliens had adapted to certain background noises and ignored them or they'd attack everything, but would respond to sudden, foreign noises, like how you will react more to a random knock on the door than the idle hum of a computer interesting to see that sound level may play a part...

I think I can live in a waterfall cause I would be hydrated and the unholy angels couldn't hear me

9:05 I did not know this for certain before, but I did some how thought I could hear things better at night for some reason. If nothing else it is less of a suspicion and more in the realm of plausibility.

I'd heard people at my summer camp say that they could hear people having conversations across the lake if they were awake early enough, it's wild to find out 15 years later WHY

I absolutely LOVE that I've wondered if sound travels differently in different temperatures and I've learned that it does from my interests and preferences i.e. MatPat's Theory videos Thank you, @Film Theory for always having the answers to things that I should know like survival skills but also things that I don't need to know like the questions that randomly cross my mind 😂

As a musician, I figured it out right after i learned they had very sensitive hearing but the movie was still very well so the semi-spoiler did ruin it for me. I would have placed my portable array speakers/battery powered PA system at the door or window with the microphone plugged straight into the input, let the feedback creep slightly enough to bait them and then....well you get the idea lol. I would only do this on an island for obvious reasons.

I knew a lot of that, very interesting. I feel for the monsters. I have hyperacusis, essentially a condition which makes your sense of hearing become SO GOOD that you hear better than others even with earplugs in (I have them in all of the time usually). I was 19 when I first noticed. My stepdad, who butted heads with me those first years, said some pretty mean stuff about me when he was in his room with mom. I was at the front door which was at the opposite end of the house. I heard him "yell" the mean threats. I was a really dumb kid, so I ran to the room and put my hand through the door, looked through the hole while my arm was bleeding & gave him a threat of my own. Yes, STUPID teen lol They looked at me, then he accused me of eavesdropping... I sad "you were yelling!" Mom, who was on my side since he'd threatened me (the threat of violence he made which was what I'd heard). Mom calmed him down, then asked if I'd been eavesdropping, to which I said no. She turned to him and said "see? He wasn't." She knew I never lie. Later, I learned of the condition, and I HATE it. Imagine having extremely powerful hearing, with fire alarms, fireworks, TV, people yelling, hearing everything your neighbors say, etc... It has helped me, but I'd rather have normal hearing... It keeps me up. Years later we became friends. Good thing... He died 13 Years later (cancer, just like my biological dad who'd died when I was 16, stepdad died when I was 32).

I went to school in the desert, and we learned about how our sound is less loud on very hot days. Then I moved up north where it snows, and I caught on to just how loud my band sounded in winter. Not only does it affect pitch, but volume.

That sound refraction is actually kinda scary. In Washington DC, where I live, there was a concert a couple weeks ago on an overcast day. The sound refraction pretty much made it a city wide block party where residents could hear the music up to 4 miles away. It only got louder as night fell. So imagine my surprise when I hear that the neighbor I thought was having a party was halfway across the city.

Me, who plays four different instruments, including violin and piano: *my time has come.*

ok so major props for the aoucstic research! I'm a musician with a bach. in composition. And am currently in my master's in sonology. Basically I make software for musicians, this involves, synthesis, sound localization/spatialization and have a modest background in physics as a dropout (mainly the campus that I was studying physics was not interested in acoustics, hence why I changed to music aimed at technology for musicians) So I did a simple spectrum analysis to figure out the pitch. And actually it's fairly consistent, it just phases in and out. It's a slightly flat G. Specifically G7, around 3096 hz. Cool thing about resonant frequencies though..... You don't need to play a specific frequency, but a harmonic of that frequency. In other words, ANY slightly flat G , be it low pitched or not, would make the body of the creature get into a ressonant frequency. So my take on how to fight these creatures.Get a brass instrument (type not necessarilly material) like a horn (which is already in G), trumpet, trombone, flugelhorn, you get the point.... Play that Mf as loud as possible. For reference, a "fff" i.e fortissísimo, on these instruments is around 130 db (possibly more). That is well enough to make those things vibrate violently. Get a whole group of people, like a marching band.... You WILL make these things "pop". Another thing, why no one used anechoic chambers?

8:40 both come into factor, considering that humans are mainly reliant on vision for precise movement and the monsters aren't bothered by the dark.

Another brilliant episode. What decibels is one of those dog whistles, I wonder if they would work?

Huh, I didn't know that cold air/night affected sound. That explains why everything at night sounds incredibly loud...I thought it was just the knowledge that people were sleeping nearby that made it seem so loud

Why does the screaming picture look so much like Dustin Henderson?

As someone who has sensitivity to sound, I can sympathize with the aliens wanting quite lmao

Really fascinating episode, a cool deep-dive into ‘A Quiet Place’, but I really did learn some stuff outside of it too! I love this channel 😌✨

this man goes so deep into detail and pinpoint information and i love it, (also everytime i eat i watch your food theories)

Here's the thing though: They go after wildlife too. The racoons near the beginning get axed relatively quickly, and its established that the DAs aren't hunting for food. They just reflexively destroy anything that's too "loud" to them. I can imagine they 'tried' to stop things like waterfalls or thunderstorms, but since there's nothing they could do they just learned to avoid those places since it would make them "go blind," so to speak. The long and short is that while there is little they could do to deal with things like swarms of noisy bugs, Earth's ecosystem is about to go fubar regardless.

It will always amaze me how much attention matpat puts into his theory

Mat is one of the best you tubers out there he keeps you watching with jokes, interesting topics and science for science lovers like me

me who plays cello: *dead*

I got a good theory idea: Can the Death Angels be controlled? They hunt by sound right? So what if their future predator vision makes them weak to a high enough decibel. But what if there was a certain frequency that makes them docile and can make them obedient?

I am an audio engineer, I am impressed that they have that level of detail in the movie, because the natural noise floor is about 40 to 50 decibels... so they can't hear you below that because that is just idle sound in the air. The noise floor is when we can't crank sound any louder, because you start getting background noise. Also, feedback loops can be at multiple frequencies at once, normally it is just one though. Also, if you really wanted to get into it you could start talking about Comb frequencies, but I don't even fully understand those.

As a musician, and one that over analyzes everything, this was pure delight to think of my instrument as a weapon.

All i can say is “ poor Jogger” XD funny and interesting video, thank you! Also what about using sound proofing rooms?

I always thought it wasn't based on how loud you were, but how out of place the sound was. Similar to the vibrations in the sand for the sand worms in Dune. You need to be quiet for short sound, so instant sounds (sneezing, coughing) that aren't too loud.

I can imagine someone about to be attacked by like 5 death angels and then someone with a flute comes along and they all just spontaneously combust

At 11:03 I started dying laughing because that’s a hearing aid, not a cochlear (I am partly deaf in both ears).

I’m an audio engineer and I’m very happy to see a theory shift from chemistry and physics to the science of acoustics:) New level of engagement… Is this how physics buffs experience game theory :) ?

It's the little things that make scenes like this genius. He uses the megaphone to talk to the man right next to him, then shouts the question to the troops far away. It's subtle. They don't even acknowledge the fact that he is doing it. :-D

I would love to see a theory about what kind of pets you could have in a quiet place tbh

They are attracted by noise... Hurricanes, earthquakes, tornadoes and thunder storms all create a lot of noise and with 3 of those being destructive, not all of the noise is exactly natural. Can the monster survive the torture mother nature throws at us on a regular basis?

I new sound was "louder" or something, but I didn't know the science thanks Matpat! Love your vids!

No way could you hear someone having a conversation from over 3 miles away on a cold day! Even if that conversation was being had with megaphones, you'd still hear nothing. It might be possible to hear someone shout in a 3 mile long tunnel.

I haven't watched a theory video in so long, forgot just how much detail this man goes in to🤣

One thing I like about both movies, many of the monsters have varying levels of intelligence and hearing skill

I’m a clarinet player and I mastered being quiet. We’re not allowed to eat in class. I was able to open a bag of chip and eat it all. I’ve done this multiple occasions and nobody notices unless I throw away the bag in the recycle

matpat finally explains why opening the microwave at 3 am is a billion times louder than opening it at 3pm

you were ON POINT until you reached the feedback tone from that implant! the tone played in the film is actually a combination of sounds resonating at the same time, and what you needed to do is isolate all the tones and find the one(s) that has zero variable.

Good thing I played the flute for two years in middle school. I went to school that filtered into Walton Highschool in Georgia so I was, and still am pretty good at it, I played things like the tempest after my first few months of my first time ever playing the flute.

I’ve been a fan of game theory and NEVER ONCE heard about MatPat playing the viola !! I’m really shocked and honestly super happy since I’ve been playing since middle school

Imagine a badass scene where the death angels are on the MC's trail, pursuing them as the survivors try to find a new place to bunker down. And then, just when the monster hears the smallest 'crack' from their footsteps, it comes running, only to be stopped by ol' Cotton Eye Joe stepping out from a barn with his squeaky violin. Joe plays so horribly the monster opens up its plating, where then Joe shoots it with a shotgun.

How to destroy a death angel IRL!1! 😱 Step one: (Never gonna give you up, never gonna let you down, never gonna run around and, desert you. Never gonna make you cry, never gonna say goodbye, never gonna tell a lie, and hurt you.) Sound: 99999 DCB

Yeah that's what I thought when a saw this. You could just surround yourself with sound waves and creat an area that they are effective blind in. Bombard them with such a large amount of audio stimulus that they simply can not make out any specific sound or direction. It's basically how you Jam a radio.

I learned something with the temperature and volume thing. I guess that's a reason why it's so hard to talk in a hot tub or dry sauna.

when it comes to walking barefoot being quiet I can 100% confirm that. I walk barefoot pretty often and if it were not for my keys i would almost make no sound at all while walking (or even running depeding on the ground). In cities this effect is actually at its maximum because you can see whats on the ground, the ground itself does not make a sound while stepping on it, and its just really smooth most of the time so nothings gonna hurt you (unlike in some woods I could mention). But yeah, walking barefoot (espcecially in cities) will make you alsmot be completly silent. At least that is my experience

As a music student,this one goes for all of my fellow musicians who had people saying that studying music is useless XD

8:25 That explains why I feel like the music I listen to is suspiciously louder at night than it is in the mornings whoa

BRO You had a joke opportunity to replace hiding with Hyden in the title

Load up on Merzbow and or experimental synthesizers. Id just make really disturbingly high pitched one in absynth and blast them with it at high volume. But you want to figure out what pitch creates the most resonance and causes the most discomfort to them. And you could probably make masking noises that cover a wide area to confuse them. Or how about infrasound?

I like the image this gave me of a lone hero walking around with a flute in a sword sheath in such a world, saving people in need.

I love that he takes temperature into account to specify his answer to a single decibel, but forgets trees exist

From all of this talk of sound has got me wondering, "Has someone died of Taco Bell?"

I would say living right next to the ocean would be desirable. Alot of sand for muffled movements, Constant running water via the waves and plenty food source via fish

ngl, I could go for some of this silence in the world. it's pretty loud and it quite honestly... i get why the death angels are against the idea 🤷🏼‍♂️

Thank you MatPat, I now know how to survive in a relationship!

Honestly surprised that MatPat concluded that the reason they shook was because the sound matched the reasonant frequency of the armor. As a physics student, I've worked with reasonant frequencies a lot, and even when working with pipes and stuff (which are not attached to vibration absorbing flesh), you need a lot of energy to cause things to shake like they do in that scene. You would not see vibrations of that scale caused by the sound produced by the implant, it's simply not possible, there is too little energy involved. Ironically, the theory he brushed aside initially is much more plausible, that there is some neurological response to those frequencies (think nails on a chalkboard for humans).

I’m going to be honest, this is the first video by this creator I have ever watched. I’ll be honest, I was really not expecting genuine calculations! The beginning of the video was super awesome! I learned so many random things about sound

I feel like for the whole corn thing it became a recurring sound like how they probably would be alerted to a fruit dropping of a tree until they got used to it

I don't think you need to always keep it under 50 dB no matter what. Earlier on in the video it is mentioned of how the sound level differed based upon the distance of the sound. I believe that would make it quite possible to have a normal conversation, as long as there aren't any death angels with a large distance.

Bruuuuh I’ve always wondered whyyy the same volume during the day was lower than during night! This was super awesome info for a life long question lol

fun fact: Cellos would trigger the death angel's weakness, not normally, but heres how 1: find the high pitch string 2: go to the same string, but under the bridge 3: take the bow and use the side 4: trigger not only the death angels, but also your friend's instant death (dear god I hate that noise)

matpat your videos are so interesting i will watch a video like this even though its about math

Meshuggah being musicians would just riff the monsters away with their godly musical ability

I’m glad to know that as a flute/piccolo player that I would survive 😂

yknow, the weakness of the aliens from a quite place reminds me of this trshow.info/watch/aTe0MjAZvMU/video.html

I always thought that it being louder at night was just because there's less ambient noise to drown it out, but, no, it was because it was actually literally just simply actually louder...

Ok but hear me out. Those consert sound systems that can literally go so loud you can feel the ground shake under your feet.... Hook them up to the high frequency audio... Lure the aliens to them... And watch as they shrivel and maybe even explode like one of those classes...

y'know sometimes i wonder how im not failing math and science, then i remember i watch you.

Love how mat uses actual science man shouldent be a youtuber he should be a teacher

FINALLY! Someone is with me on my corn nit pick! The corn took me out of the movie the first time I watched the movie and I haven't let it go.

Finally, a theory I could nerd out on. I wrote half a book detailing all the ways you could use a DAW to defeat the Death Angels, but thought better of it. I'll just say this was probably the first theory I *_REALLY_* got into. Not to say I don't like the other theories, but...musician brain is going crazy.

Thanks matpat I got A+ on my physic exam because of you.

theory time: when you call two phones on speaker and put them next to each other and start yelling into both of them, idk why but it starts turning into a siren like noise that's really high pitched and goes on legit forever. idk maybe that could work???

Deaf people in a quiet place: " My strength and my weakness at best, a challenge indeed"

One of my friends is super sensitive to sound and by playing the E string bellow the bridge on the violin, will create a HORRIBLE sound so beware

The biggest problem with the whole movie is that you have an enemy that hunts by sound. Yet the military didn't immediately try to use some type of sound against it? It's like have a nocturnal predator and no one figuring out that if you have bright lights, you can disable it. I still liked the movie but thought it was weak that it took an accidental discovery for what would have likely been found in the first day or two of fighting.

This was very interesting. I'm going to have to see, if I can find the movie now

I would get one of those little devices that emit a certain pitch so I can’t hear it but it drives the monsters insane but they can’t get close

Ugh!!! That scene of her stepping on a nail made my toes curl! I stepped on a nail once at a summer camp, and it was not pleasant!

Both A Quiet Place movies are freaking amazing you can't tell me otherwise

The Quiet Place + Bird Box + Weeping Angels + SCP-173 is possibly the worst sensory death combo. I am open to more suggestions

I've always thought "like what if people just made enough sound where the creatures went deaf. Like it wouldn't take nearly as much as a person, and the sound of civilization would almost certainly sensory overload them instantly."