Wearing earplugs will make your voice louder. Why?

Briefly talk about what causes hearing loss. In our inner ear, there is an organ called cochlea, which is different from the function of collecting and transmitting sound from the outer ear and amplifying sound from the middle ear. The function of the cochlea is to convert sound signals into electrical signals for the brain to understand, and the acoustic-electrical conversion is realized through hair cells in the cochlea. What are hair cells? Let me show you a photo:

This is an electron microscope photograph of healthy inner and outer hair cells. The lower three rows are the outer hair cells of the cochlea, and the upper row is the inner hair cells. These two groups of hair cells play different roles. Let's talk about inner hair cells first. There are about 3000 inner hair cells in the left and right cochlea, and each hair cell has 40-60 cilia. Its main function is to transmit sound to the brain for us to hear. The outer hair cells are different from the inner hair cells in shape and number. There are 65,438+02,000 outer hair cells in each cochlea, and each cell has about 65,438+000 cilia. Cilia has two main functions: one is to amplify the tiny sound of 40-60dB SPL, and the other is to distinguish the differences of tones. The effect of listening in noisy environment also depends on whether the outer hair cells are healthy or not. There are tiny cilia on the inner and outer hair cells, which help the cochlea feel and transmit sound. If exposed to noise for a long time, these hair cells will be mechanically damaged under excessive compression. And the damage is irreversible. This is a micrograph of damaged outer hair cells. The damage of outer hair cells is very serious, which will lead to 40-60dB of hearing loss, and the loss is irreversible. If the damage continues to expand, the inner hair cells will also be damaged, which will lead to serious or extremely serious hearing loss. For details, please refer to anonymous students': Safe time for normal ears to be exposed to different sound pressure levels. Here, I'll tell you a principle of listening to music with headphones: the 60/60 principle, that is, the use should not exceed 60% of the overall volume and the duration should not exceed 60 minutes. I often meet classmates listening to music with ipod in the elevator, and the volume is so loud that everyone in the elevator can hear it, which is very unsafe. If you must listen on the road, try to use earmuffs instead of plug-in headphones.