The unit of loudness of sound is , and the loudness of the smallest sound that the human ear can

Loudness, also known as sound intensity or volume, indicates the intensity of sound energy, which mainly depends on the amplitude of the sound wave. The loudness of sound is generally measured in terms of sound pressure (dyne square centimeter) or sound intensity (watt square centimeter), the unit of sound pressure is Pa (Pa), and the logarithm of its ratio to the reference sound pressure is called the sound pressure level, and the unit is decibels (dB). For the psychological perception of loudness, it is generally measured by the unit sone, and the loudness of the pure tone of lkhz and 40db is defined as 1 song.

The relative quantity of loudness is called loudness level, which represents the logarithmic value of the ratio of a certain loudness to the base loudness, and the unit is the phone, that is, when the human ear feels that a sound is as loud as a pure tone of a single frequency of 1kHz, the decibel number of the sound pressure level of the sound is its loudness level. It can be seen that both objectively and subjectively, the concept of these two units is completely different, except for the pure tone of 1kHz, the value of the sound pressure level is generally not equal to the value of the loudness level, and it should be paid attention to in use.

Loudness is the basis of hearing. The intensity of normal people's hearing ranges from 0db to 140db (some people think it is -5db to 130db). It is true that sounds that are outside the audible frequency range (i.e., frequency domain) of the human ear cannot be heard by the human ear, even if they are louder (i.e., the loudness is zero).

However, in the audible frequency domain of the human ear, if the sound is weak or strong enough to a certain extent, the human ear is also inaudible.

Subjectively, loudness is a subjective measure related to the intensity and frequency of sound. Acousticians use a pure tone of 1000 Hz as the reference tone, and when its sound pressure level is 40 dB above the threshold, its loudness is 1 sone. If the loudness of a sound is judged by the listener to be n times that of 1 song, the loudness of this sound is n song.

According to psychophysical experiments, the standard loudness of a 1000 Hz pure tone is a power function of its physical intensity, that is, l = is the loudness, and the unit is Song; i is the physical strength; k is a constant. That is, loudness varies with the power of sound intensity. According to the above formula, for every 10 decibels increase in sound intensity, its loudness increases by 1 dB.

You can only provide this information, and judge for yourself.

Sound characteristics. 1) Loudness: The magnitude of the sound subjectively felt by the "amplitude", the larger the amplitude, the greater the loudness. (Unit: dB dB).

b) Pitch: The pitch of the sound, determined by the "frequency", the higher the frequency the higher the pitch (frequency unit Hz, hertz [url, human ear hearing range 20 20000Hz) for example, the sound of the low end or the sound of a higher one, such as a thin string.

3) Timbre: The characteristics of sound are determined by the material and structure of the object itself.

Frequency is the number of sound waves passing through a given point per second, and it is measured in hertz and is measured in the name of a person named Herich RHertz's Acoustic Wonder is named. This person sets up a table and demonstrates how the frequency relates to the period per second.

1 kilohertz or 1000 hertz means that there are 1,000 cycles per second for sound waves passing through a given point, 1 megahertz means 1,000,000 cycles per second, and so on.

1. The loudness of the sound is related to the amplitude of the emitter (the maximum distance of the object from the equilibrium position), and the greater the amplitude, the louder the louder.

2. The loudness of the sound is related to the distance from the sound emitter, and the farther the distance, the smaller the loudness. Substance: It is related to the concentration of sound waves, and the more concentrated the louder. If the sound wave is dispersed and the loudness is smaller, the sound is far away.

3. The loudness of the sound is related to the medium through which the sound wave is propagated. Under the same conditions, the loudness is generally different in different media.

Volume is used to describe the strength of a sound, commonly known as the "magnitude" of a sound. It is determined by the amplitude of the vibration of the sound source, the greater the amplitude of the vibration, the stronger the sound; The lower the amplitude of the vibration, the weaker the sound.

Pitch is used to describe the pitch of a voice, commonly known as the "sharpness" of a voice. It is determined by the speed of the vibration of the sound source, the faster the vibration, the higher the sound; The slower the vibration, the lower the sound. High-pitched sounds are light, short, and thin; The pitch is heavy, long, and thick.

Timbre is used to describe the characteristics of a sound and is related to the characteristics of the emitter itself. Timbre is the basis by which we distinguish various sounds, regardless of volume and pitch. Even if different instruments produce the same volume and pitch, it is easy for us to identify the type of instrument, and this is due to the different timbres.

First of all, the height of the sound, from the physical concept, the level of the sound is determined by the vibration frequency of the object, the higher the vibration frequency, the higher the sound, on the contrary, the more sound; So from the perspective of quality, the height of the sound constitutes the main body of the melody, the melody goes from the bass to the high note, and then to the high note back to the bass, and the continuous ups and downs develop, constituting the beautiful ** sentences we hear. So when we combine it with practical applications, the vibration frequency is the number of times an object vibrates per unit time, for example, the number of times a guitar string vibrates in a second is definitely faster than the number of times a bass vibrates in a second; For example, when we sing high notes, we need more breath to pass through our vocal cords at a faster speed to make the vocal cords vibrate faster.

Let's talk about strength again, strength is actually the size of the sound, or from the physical point of view, the size of the sound is determined by the amplitude of the vibration of the object, the greater the amplitude of the vibration, the louder the sound, the smaller the amplitude of the vibration, the smaller the sound; From the point of view of sexuality, the strength of the voice constitutes the main body of emotional expression, each paragraph is to express an emotion, emotion or picture, then the heavy or light, strong or weak, soothing or rapid conversion between the two, constitutes a different emotional sense, giving the audience different emotional feelings. Combined with practical applications, it is still a guitar string, and if we want to make it make a bigger sound, we need to pull it farther away from the original position, so that it has a greater vibration amplitude, so that it can make a bigger sound.

This is expressed according to the sound you hear, if you say that the louder the sound you hear, then it means that the sound is stronger, if you say that the sound you hear is smaller, it means that the sound is particularly weak.

It is usually expressed in decibels, it is also the unit of sound, if the sound is relatively loud, the decibel is still relatively large, the sound is relatively small, and the value of the decibel is also relatively small.

Usually expressed in decibels, or dB, a decibel is defined as a measure of the ratio of two quantities of the same unit.

The so-called hearing range does not refer to loudness, but refers to the tone, that is, the frequency of the vibration of the object, which is expressed in hertz (Hz), and 20Hz-20000Hz is the hearing range of a person.

The decibel is a division of sound intensity, and 0 decibel does not mean that there is no sound, but the faintest sound that people can usually hear, and the decibel of the sound can be heard if the decibel is high, but it will be harmful to the human body.

Hearing loss is calculated as pure tone audiometry and average hearing of air conductance in Hz. The hearing range of a normal person is between 0 25 decibels (dB).

According to the World Health Organization Grading Standards for Deafness:

26 40 dB; Mild deafness.

41 55 dB: Moderately deaf.

56 70 dB: moderate to severe deafness.

71 90 dB: Severely deaf.

Volume analogy.

130 dB Jet take-off sound.

110 dB Spiral Aircraft Take-off Sound.

105 dB Permanent impairment of hearing.

100 dB pneumatic rig sound.

90 dB Noisy bar ambient sound.

85 dB and below will not destroy the hair cells in the cochlea.

80 dB noisy office.

75 dB upper limit of human ear comfort.

70 dB street ambient sound.

50 dB normal conversation sound.

20 dB whispering.

According to the ordinary person's sense of hearing.

0 2 0 dB It's so quiet that it's almost invisible;

2 0 4 0 dB quiet, like a whisper;

4 0 6 0 dB average. Ordinary indoor conversation;

6 0 7 0 dB noisy, nerve-damaging;

7 0 9 0 decibels are noisy and nerve cells are destroyed.

9 0 1 0 0 dB Increased noise, hearing loss;

1 0 0 1 2 0 decibels are unbearable, and a minute of deafness is temporary.

Above 120 decibels: extremely deaf or totally deaf.

The strength of the sound that can be perceived by the human ear is called loudness, and the magnitude of loudness is related to the amplitude;

So the answer is: strength and weakness, amplitude

The pitch of the sound is called the pitch, and the pitch is related to the frequency of the vibration;

The strength of the sound that can be perceived by the human ear is called loudness, and the magnitude of loudness is related to the amplitude;

So the answer is: pitch, amplitude

Loudness is determined by the amplitude of the vibration of the sound source, the greater the amplitude, the greater the loudness; It is also related to the distance from the sound source, the closer to the sound emitter, the louder it is; During sound propagation, the more concentrated the direction, the louder it becomes

So the answer is: amplitude; Distance.

1., the relationship between loudness and amplitude: the greater the amplitude of the emitter, the greater the loudness; The smaller the amplitude, the smaller the loudness.

2. The relationship between loudness and distance: loudness is also related to the distance between the listener and the sound emitter, and the farther away from the sound emitter, the smaller the loudness.

3. The loudness of the sound is related to the degree of sound dispersion, the more concentrated the sound, the louder it is.

4. The loudness of the sound is also related to the subjective feeling of the human ear and whether the sound encounters obstacles during the propagation. The amplitude of the sound source, the so-called amplitude is the maximum distance that the object deviates from its original position when it vibrates, the greater the amplitude of the sound source, the louder the sound.