Car horns on the road, birdsong in trees and people talking, beautiful music in headphones, sound is everywhere all the time, but do we really understand it? Teacher Zhang Zhibo of the Institute of Acoustics of the Chinese Academy of Sciences, take you to explore the mystery of sound together.
Professor Zhang Zhibo, Institute of Acoustics, Chinese Academy of Sciences
Inaudible sounds
Do you know how sound is produced and spread? How are we perceived in our daily lives?
Careful observation, the music can not only be listened to, but also seen. Vibrations can be seen on the surface of the loudspeaker or on the strings being played. In ancient times, there was a kind of copper basin in the mainland, fish washing, and when people rubbed on the edge of the basin, the water in the copper basin would stir up and make a humming sound at the same time.
Imagine if the alarm clock is put into a closed glass jar and the air inside the glass jar is sucked out, can the sound still be heard?
Humans have a complete auditory system to perceive sounds, but can only hear audible sounds. Infrasound and ultrasound are also sounds, but beyond the range of frequencies that humans can recognize, and are the sounds we "can't hear." Don't underestimate these inaudible sounds, in addition to music, talking, we use these inaudible sounds to achieve B-ultra inspection, determine the position of objects and so on.
The "Six-Eared Macaque" in the Instrument
Musical instruments are unique to human inventions, and every second of music requires special instruments to play.
The sounding principles of the five instruments are different, namely body instruments, membrane instruments, string instruments, air instruments and electric instruments. When it comes to the darling of musical instruments in the new era, electric musical instruments are definitely the most technologically sounding.
In 1875, Bell of the United States discovered that sound and electrical signals can be converted from each other, and thus invented the telephone, which laid the theoretical foundation for the birth of electric instruments. Modern electronic synthesizers use integrated circuits, information processors and digital processing technologies to simulate almost any instrument and any sound, and can also create sounds that are not found in nature and life, and combine the performance effects of traditional instruments.
Will algorithmic composition replace traditional music creation?
In 2017, Grammy-winning producer Alex and his creative partner "Watson" co-created a song that accommodated tens of millions of sad things, "Not Easy", which was topped the Spotify Global Chart No. 2. And this "Watson" is not a person, but a computing system.
"Algorithmic composition" as a new fashion, rely on mathematical thinking to compose music, or even completely without the intervention of composers. In addition to traditional mathematics and algorithms, modern artificial intelligence began to be used in music, creating a human-computer interaction model for computer composition.
So, will algorithmic composition replace traditional music creation? At present, this is of course a fantasy, but the future of highly developed science and technology is also unknown.
Why did humans invent headphones?
In the 1880s, the world's first pair of headphones was born. But it wasn't born out of music, it was made for communication, and headphones at that time were more like a large stethoscope.
In 1937, the German scientist Jugen Bayer invented the world's first musical headphones. So far, headphones have become one of the most convenient ways for people to listen to music, and have even been voted "one of the 100 greatest inventions in the world" by authoritative institutions.
With the development of science and technology, anti-noise headphones, earbud headphones, wireless headphones, and even bluetooth headphones, bone sound headphones and other black technologies have given headphones more functions.
What kind of building can achieve "three days around the beam, the afterglow of the sound"
Listening to music with headphones is convenient, but for many people, the stereoscopic immersive experience of the concert site is even more wonderful.
Unlike ordinary architecture, the concert hall involves many scientific theories such as music, acoustics and architecture, and is a synthesis of art and science.
The length of the reverberation time directly affects the sound effect of the concert hall, and the appropriate reverberation time should be selected according to the volume, size and sound type of the room. According to the principle of sound wave propagation reflection, designers should infer the direction and distribution of sound waves in the room, so that sound waves can be evenly distributed throughout the room in a certain period of time, so that the unique interior design can "go around the beam for three days, and the aftersound is lingering".
When art and technology are perfectly integrated, and the music is played at this time, in addition to the beautiful notes, the music hall is full of scientific and technological symbols.
The "Exploring the Mystery of Sound" series of popular science videos is jointly planned and produced by The China Next Generation Education Foundation, Shenzhen Ping An Public Welfare Foundation, and Science and Technology Daily, aiming to guide young people to observe life, explore the scientific principles contained in life, and cultivate the spirit of exploration of young people.
The series of video content has been launched on multiple platforms such as Science and Technology Daily New Media Matrix, China Science and Technology Network, Science Popularization China, Tencent Video, Watermelon Video, Baidu Baijia Number, Weibo Pan Knowledge, B Station, Youth Science and Technology Literacy Improvement Plan Public Account, KK Live, YY Live, etc. Pay attention to us to learn more wonderful content. (Zhao Weihua)
Source: Science and Technology Daily