Can infrasound and ultrasound sound be emitted?

The general sound cannot be emitted, and the sound waves heard by the human ear are 20---20000hz. Many speakers can't be covered, such as: 60---18000Hz.

Some high-class speakers can emit ultrasonic waves of 30,000Hz. There are no speakers that can produce infrasound, because many speakers can't even emit 20Hz, let alone infrasound.

The ears of those who send it out cannot hear.

A good tweeter can emit ultrasonic waves at partial frequencies, but the efficiency is so low that people themselves can't hear it.

No matter how good the civil woofer is, it can't emit infrasound, so it has to be done exclusively by the dogs, used to suppress violence, and pulled by trucks, which shows the low efficiency, and they can do good things?

The human ear can't hear the infrasound, but the body will be shocked, the internal bleeding will be inside, and the body will faint. The next time I gather, I saw the dogs' special car carrying a black box that seemed to be able to make a sound, flash! Big move! Stay away!

Modern audio equipment is hi-fi, which can emit infrasound waves (below 16Hz) and ultrasound waves (above 20,000Hz), but the human ear can no longer hear them.

The principle of infrasound is that it can emit a large amplitude, and the frequency can resonate strongly with some organs of the human body to destroy people's internal organs and kill people.

The sound power is very small, even if the frequency and human internal organs can resonate, people can't feel it at all.

In fact, people usually live with infrasound, sound waves, and ultrasound, but our ears can only distinguish sound waves.

Due to the short range of other detection methods, the penetration ability of light in the water is very limited, and even in the clearest seawater, people can only see objects within tens of meters to tens of meters; Electromagnetic waves also decay too quickly in water, and the shorter the wavelength, the greater the loss, even if high-power low-frequency electromagnetic waves are used, they can only propagate a few tens of meters.

However, the attenuation of sound waves propagating in the water is much smaller, in the deep-sea channel, a bomb of a few kilograms, 20,000 kilometers away can also receive a signal, low-frequency sound waves can also penetrate the seabed thousands of meters of the formation, and get the information in the formation. No more effective means of measuring and observing in water than sound waves has been found.

Sonar. Using the propagation and reflection characteristics of ultrasonic waves in water, the technology of navigation and ranging through electroacoustic conversion and information processing, while infrasound.

It is not easy to attenuate, not easy to be absorbed by water and air, has strong penetration, and is difficult to reflect.

Ultrasonic frequency directionality is good, the reflection ability is strong, it is easy to obtain more concentrated sound energy, and the propagation distance in the water is long, which can be used for distance measurement, velocity measurement, etc., and is suitable for underwater detection. The invention of sonar was inspired by bats. The ultrasonic waves emitted by bats are reflected back when they encounter obstacles, and they can quickly determine what object is in front of them, how far away they are, whether it is food, tree trunks, or enemies, and then decide to attack or dodge.

Infrasound waves are not easily attenuated and are not easily absorbed by water and air. Infrasound waves are extremely penetrating, not only through the atmosphere, seawater, soil, but also through solid reinforced concrete buildings, even tanks, **, submarines and airplanes. The lack of reflective properties means that infrasound waves cannot be used in sonar equipment.

Ultrasonic waves are highly directional and prone to reflection when encountering objects; Infrasound waves are not directional and are not easy to be reflected (the scale of the object is greater than the 1 4 wavelength of the sound wave is easy to reflect); Sonar detection uses the reflection of sound waves to find objects, so ultrasound is used;

The infrasound frequency is too low and the wavelength is too long. Not suitable for high-speed signal modulation, etc.

1. Ultrasound.

Ultrasonic is a kind of sound wave with a frequency higher than 20,000 Hz, which has good directionality, strong penetrating ability, easy to obtain more concentrated sound energy, and has a long propagation distance in water, which can be used for distance measurement, speed measurement, cleaning, welding, stone crushing, sterilization and disinfection, etc. There are many applications in medicine, military, industry, and agriculture. Ultrasound gets its name from the fact that the lower limit of its frequency is greater than the upper limit of a person's hearing.

2. Infrasound.

Sound waves with a frequency of less than 20 Hz (Hertz) are called infrasound. Infrasound waves are not easily attenuated and are not easily absorbed by water and air. Infrasound waves, on the other hand, tend to have a very long wavelength, so they can diffract around some large obstacles.

Some infrasound waves can circle the Earth for 2 to 3 cycles. Due to the similarity or even the same vibration frequency as the vibration frequency of human organs, infrasound waves of certain frequencies are easy to resonate with human organs, which is very harmful to the human body and can cause death when dangerous.

Ultrasound is a type of mechanical wave that has a much higher frequency than the sound that can be heard by the human ear. In general, we call sound waves with frequencies greater than 20kHz ultrasonic. Therefore, ultrasound has no sound because sound refers to perceptible sound waves that we can hear.

However, although ultrasound waves cannot be heard, they have a wide range of applications in the medical and industrial fields. For example, in medicine, ultrasound can be used to examine a pregnant woman's fetus, watch for heart disease and other abnormalities in internal structures. In addition, ultrasonic waves are used in the industrial sector to detect defects in objects or to perform non-destructive inspections.

It is worth mentioning that although humans cannot hear ultrasound, certain animals such as dolphins, bats, etc., can use ultrasound to locate and hunt. This phenomenon is known as bioultrasound.

So, in general, ultrasound has no sound, but they have a wide range of uses in a variety of applications.

In addition, it is worth noting that the application of ultrasound has a lot of potential for expansion, and it has a wide range of uses in industrial, medical, military and other fields. For example, with the development of technology, there are already some new types of devices that use ultrasonic technology to erect the skin. Therefore, with the continuous development of science and technology, ultrasound will play an important role in more fields and create more value for human beings.

1. The propagation of the vibration of the emitter in the air or other substances is called sound waves.

2 Scientists call the number of vibrations per second the frequency of sound, and its unit is hertz (Hz).The frequency of sound waves that our human ears can hear is 20Hz-20000HzTherefore, we call sound waves with frequencies higher than 20,000 hertz "ultrasound".

Obviously, sound waves contain ultrasound. This question is somewhat similar to whether food and rice are the same thing? The answer, of course, is: not the same thing.