Here is about ultrasound, one of the sounds emitted from animals!
The animals using ultrasonic waves are various. Among them, I would like to take up the bats and dolphins that came out this time.
Bats
Bats utilize ultrasound to avoid obstacles in dark caves。
Ultrasound is emitted from the throat, and ultrasonic waves reflected from obstacles are used to accurately grasp the position information！
This is called echo lotion (echo localization).
So, how does the bat specifically recognize the position of the object？
It is as follows.
@Distance Measure the distance to the target at the time from the time when the ultrasonic wave is emitted until it is reflected to the object and is heard.
ADirection The direction of the object is recognized from the angle of the reflected ultrasonic wave .
BSpeed When the object is moving, the frequency changes depending on what is called the Doppler effect. From that information you can know the speed difference from the object.
Cvolume Depending on the size of the reflected wave , you can see the size of the object. For small ones, the area of the reflecting surface is small, so the reflected ultrasonic waves become smaller.
DMove If the object is vibrating, the amplitude and frequency of the reflected wave will change . You can guess the movement with that difference.
Bats are based on ultrasonic information and can judge surrounding circumstances, you can take food and avoid obstacles . The high performance so far is amazing!
Dolphin
Dolphins are also ultrasonic animals . Especially has a body structure that effectively transmits and receives sound waves.
@Pronunciation organ By sending air to the folds in the middle of the respiratory tract , ultrasonic waves are generated.
AMelon organ refracts the ultrasound and converges it to one part with a fat mass in the dolphin's forehead as the "acoustic lens".
BBone in the upper jaw
Bones like a parabolic antenna,It reflects sound in one direction .
Dolphin is a very precise body structure that is effectively utilizing ultrasound!
Finally, of the sounds emitted from animals, it's about mosquito sounds!
Mosquito sound is an unpleasant sound emitted by mosquitoes.
" that sound "that pleasant sound is heard when there are mosquitoes near the summer 's day.
Like a
Especially when I hear it before going to bed I am annoyed and can not get to sleep at all.
But,Some people do not think so at all. Why is that?
Actually, there is also frequency involved there !
Mosquito sound (mosquito) is the sound from 17000 Hz to 2000 Hz when it is set to the frequency. The frequency of this mosquito sound is located on the higher side among people's frequencies. (* See above)
So, what will happen if you make it to the actual sound? Let's experience!
※ Pressing the play button will produce a sound. Volume・Listening attention.
16000Hz
17000Hz
18000Hz
19000Hz
20000Hz
How was it? Have you heard too much and do not feel bad ...?
But How you feel with age will change.
As people go years ahead, the width of the sounds heard will narrow down. In short, the mosquito sound, which is gradually high-frequency, can not be heard.
So, Even though we are unpleasant for young people, it is not felt uncomfortable for those who are middle- to high-rise people!
