Les animaux comme les chats, les chiens, les éléphants et les humains ont des oreilles saillantes qui aident à canaliser les vibrations sonores vers leur oreille interne ! Les dauphins, en revanche, n'ont pas d'oreilles externes mais possèdent une des meilleures capacités auditives qui soient. Les scientifiques pensent que les dauphins utilisent une partie de leur mâchoire pour envoyer des vibrations à leur oreille interne. À l'intérieur de l'oreille interne, ces vibrations se dirigent vers la cochlée, qui est remplie de minuscules cellules ciliées qui aident à détecter les différentes fréquences sonores. Plus la cochlée d'un animal est longue, plus elle possède de types de cellules ciliées, lui donnant ainsi une plus grande variété de capacités d'audition. Assez cool, n'est-ce pas ? Animation créée par Sympa.
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Musique par Epidemic Sound https://www.epidemicsound.com
Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna
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Nos réseaux sociaux :
Facebook: https://www.facebook.com/sympasympacom/
Instagram: https://www.instagram.com/sympa.officiel/
Stock de fichiers (photos, vidéos et autres):
https://www.depositphotos.com
https://www.shutterstock.com
https://www.eastnews.ru
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Si tu en veux encore plus, fais un tour ici:
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FunTranscript
00:00Since immemorial times, humans have been sharing the planet with other species.
00:05Each one having a unique perception of reality in terms of color, speed and sound.
00:11Today, thanks to technological advances,
00:14we are able to understand how animals perceive our sound universe.
00:18So, why not try to see the world through their ears?
00:22Let's start with man's best friend.
00:24The dog.
00:25It is well known that dogs perceive time differently from us.
00:30The most common idea is that a human year would be equivalent to 7 years of dogs.
00:35But what do they perceive exactly when we call them by their name?
00:39Dogs experience the world more slowly than we do,
00:43affecting their perception of time, but also of sound.
00:47Let's say you called Medor to go for a walk.
00:50You speak at a normal pace, as usual.
00:53But for Medor, your voice seems slowed down,
00:56as if you had set the reading speed to 75% on a music app.
01:02You probably heard that dogs have a wider range of hearing than humans,
01:07and that they can capture sounds at great distances.
01:10It's quite true.
01:12The average human ear perceives sounds between 20 Hz and 20 kHz,
01:18with a better hearing among young people, which tends to decrease with age.
01:23It is scientifically proven.
01:25On the other hand, dogs can hear up to 45 kHz, well beyond our perception.
01:32Some breeds of dogs known for hunting require a particularly fine hearing.
01:37However, dogs are not as skilled as we are to recognize sounds.
01:42Where a human can easily distinguish A-B from B-C,
01:45a dog does not show such a discernment.
01:48This is called frequency selectivity.
01:51The scientific explanation for this is that different parts of the cochlea respond to different frequencies.
01:58This is what the human ear looks like from the inside.
02:02And this is what a dog's ear looks like.
02:05The cochlea, this spiral-shaped structure, is filled with a liquid similar to salty water.
02:12At the heart of the cochlea are tiny hairs that vibrate according to the frequency of the sounds received.
02:19Some of these hairs are activated by high-pitched sounds,
02:22while others react more to lower notes.
02:27Dogs really seem to be the best friends of man,
02:31and even share our tendency to lose hearing as we age.
02:35Human hearing is at its peak in our youth.
02:39A study from the University of New South Wales
02:42reveals that a child can hear sounds up to 24 kHz.
02:46This ability to perceive very high-pitched sounds decreases with age,
02:51and an elderly person can no longer hear anything beyond 8 kHz.
02:56This means that she can probably no longer hear the birds singing or even the sound of the microwave.
03:02In dogs, as in humans, this loss of hearing is linked to the degeneration of the small hairs in the cochlea.
03:09And what about cats?
03:12They can hear frequencies even higher than dogs,
03:16going slightly beyond 60 kHz.
03:19This ability is particularly useful for hunting small rodents
03:23that emit sounds almost imperceptible to humans.
03:26Thanks to its fine nose, a cat can detect a mouse hidden in a bush more than 30 meters away.
03:34Curiously, while dogs perceive the world more slowly than we do,
03:39cats experience life about 9% faster than we do.
03:44You have probably heard of infrasound and ultrasound.
03:49Let's play a little game.
03:51We will give you an example of sound, and you will have to guess whether it is an infrasound or an ultrasound.
03:57Would you say that the sound of moving tectonic plates is an infrasound or an ultrasound?
04:02The correct answer is infrasound.
04:05Here is another example.
04:07The movement of ants in an underground tunnel is also an infrasound.
04:12Infrasounds are sounds of very low frequency, below 20 Hz,
04:16that we cannot hear, but that elephants can perceive.
04:21When you look at elephants, the first thing you notice is their big ears.
04:27Everything in their house is quite imposing, but their ears are quite remarkable compared to ours.
04:34These large leaves of cabbage allow them to capture much longer sound waves than the ones we are used to.
04:41This means that they can detect the movement of clouds and physically hear the approach of rain.
04:47This ability is precious to them, because it tells them when to go to the sources of water, for example.
04:54Elephants also use infrasounds to communicate with each other by hitting the ground with their feet,
05:01thus generating powerful, but almost inaudible vibrations.
05:05Thanks to the nerve endings in their feet and their bones,
05:09they can capture these vibrations, a bit like a phone call.
05:14Speaking of vibrations, how can a snake be charmed by a flute if it has no ears?
05:20In reality, the snake does not follow the music, but the light tapping of the charmer's feet on the ground.
05:27For humans, sound waves are mainly carried by the air.
05:32On the other hand, snakes, in direct contact with the ground, perceive the environment through vibrations.
05:39Devoid of earplugs, their inner ear is connected to their jaw.
05:44In addition, vibrations are transmitted from bone to bone inside the snake,
05:49a phenomenon known as osteophony, literally meaning that snakes listen with their bones.
05:55If it worked that way for humans, sound waves could literally cause shivers along our spine.
06:02Well, humans listen to us through the air, elephants and snakes through the ground.
06:07But what about aquatic animals?
06:11Contrary to what one might think, water does not impede the hearing of dolphins.
06:15They emit sound waves of very high frequency, classified as ultrasound.
06:21They produce clicks in order to scan their environment in search of food and other animals.
06:27The sounds that come back to them allow them to precisely identify what is around them.
06:32To put it simply, dolphins see with their ears.
06:36This ability, called echolocation, is a form of navigation by sound.
06:44You've certainly heard of sonar, haven't you?
06:48This instrument is used by ships to detect objects underwater.
06:52A sonar emits rapid sound impulses that bounce off the seabed and return to the sender,
06:58allowing them to measure the depth of the water, locate wrecks and discover geological formations.
07:05This is exactly what dolphins do to locate themselves in their environment.
07:09According to National Geographic, humans can detect frequencies reaching 100 kHz
07:15when they dive underwater, almost equal to dolphins.
07:19Imagine using echolocation to locate yourself underwater.
07:23Scientists do not understand exactly why this happens, but they have two hypotheses.
07:29This could be related to the way sound spreads differently through water,
07:34or to the way our ears process sound in this environment and how our brain interprets it.
07:40It is not only dolphins that use sound to locate themselves.
07:44bats do the same.
07:46Living often in dark environments, or even totally dark,
07:50they cannot really count on their vision.
07:53However, their hearing is so developed that they practically do not need their eyes to move.
07:58Although the brain of a bat is small, it can map its environment in detail,
08:04allowing it to easily locate its prey.
08:07What about rodents?
08:09If you have ever observed a mouse or a bat,
08:12you have probably deduced that they were born on springs.
08:15Funny fact!
08:17Compared to humans, a bat perceives the world around it at twice the speed.
08:22Thus, what seems fast and nervous to us seems rather calm from the point of view of this rodent.
08:28In terms of hearing, a mouse can hear up to 91 kHz, which is incredibly high.
08:36Fascinating, isn't it?
08:39For more UN videos visit www.un.org