Why can the human ear hear all kinds of sounds?

Sound only needs the vibration of the sound emitter, and the sound must first meet the vibration of the sound emitter, and it must vibrate 20 times per second 20,000 times, and then there must be a medium for transmitting sound, and then there must be a normal and good organ (human ear) to receive sound, these three conditions are indispensable. The physical process by which a person hears sound. There are several routes for the human ear to hear the sound.

The physical process by which the human ear hears sound: the emitter vibrates The sound travels in the form of sound waves in a medium The human ear receives sound waves to cause hearing. In fact, the sound heard by the human body is transmitted to the inner ear by two routes, namely air conduction and bone conduction.

1) Air conduction: Sound waves are collected by the pinna and transmitted to the eardrum through the external auditory canal, and the eardrum vibrates, driving the ossicles and other tissues to transmit to the auditory nerve, and the auditory nerve transmits the signal to the brain, and the person hears the sound. Usually we hear sounds from other sound sources, mainly air conduction.

2) Bone conduction: Block the ear with your hand (cut off the air conduction), put the tail of the vibrating tuning fork against the forehead or teeth, and hear the sound separately, at this time, the sound is mainly transmitted directly to the inner ear through the vibration of the skull or teeth. That is, people hear their own voices that are transmitted by bones.

We can hear sound because the sound reaches our ears and can cause the eardrum to vibrate, and the process of hearing sound in the human ear is: the object vibrates to produce sound waves, and the sound waves are transmitted to our ears to cause the vibration of the eardrum, which is transmitted to the brain by the auditory nerve Different vocal bodies emit sound timbre Different people's perception of sound is to vibrate the eardrum through sound waves, through a complex system, and then to the auditory nerve, so the sound is heard. The range of hearing of the human ear to sounds of different intensities and frequencies is called the vocal domain.

Within the vocal range of the human ear, the subjective perception of sound auditory psychology mainly includes loudness, pitch, timbre and other characteristics. Different sounds have different intensity and frequency composition, that is, they have different timbres, so they can distinguish different sounds. At present, the complex mechanism of human hearing is not thoroughly studied, but more from the physiological aspect.

In physics, sound is generated by the vibration of an object, and the object that is emitting sound is called the sound source. The number of times an object vibrates in a second is called frequency, and the unit is hertz, the letter HzThe human ear can hear the sound of 20Hz --- 20000Hz.

The most sensitive is the sound between 1000hz --- 3000hz.

The propagation speed of sound in different media is generally solid, liquid and gas (exceptions: cork 500m s, less than kerosene (25), distilled water (25), etc.), and the propagation speed of sound is related to the type of medium and the temperature of the medium.

Transmission of sound in the ear: Sound from the outside world causes the eardrum to vibrate, and this vibration is transmitted to the auditory nerve through the ossicles and other tissues, and the auditory nerve transmits the signal to the brain, and the person hears the sound.