The first batch of post-90s has begun to be "deaf", headphones have become a "new killer"

Put on headphones, brush your phone, and enjoy the "loneliness of one person", which seems to be the daily routine of modern young people.

However, as the use of headphones becomes more frequent, the proportion of young people experiencing hearing loss is also increasing year by year.

This year, the World Health Organization (WHO) released a set of data:

At present, about 1.1 billion young people (12 to 35 years old) around the world are facing irreversible hearing loss due to excessive volume of personal audio devices (such as listening to music with mobile phone headphones).

By 2050, the number of people with disabled hearing loss may increase to more than 900 million, which is equivalent to 1 in 10 people with disabled hearing loss.

Such shocking data, in our daily life, seems to be invisible, ignored by too many people. Until one day, I suddenly found that I couldn't hear clearly, but it had reached the point of no return.

01. Why do headphones cause hearing loss?

We often say that the hearing loss caused by improper use of headphones is mostly caused by damage to the hair cells in the inner ear.

In each of our ears, there are about 18,000 tiny hair cells that are a vital part of the auditory system.

Auditory hair cells are very sensitive to loud sounds and are susceptible to damage or death. (Human hair cells lack the ability to regenerate, damaging one, one less.) ）

Normally, sound travels a certain distance to enter the ear, and the high-frequency part of the sound in the middle has been absorbed by the air.

Relying on headphone sound transmission, the eardrum is very close to the headphone vibration sheet, the sound wave conduction range is small and concentrated, and the sound pressure will directly enter the ear and be transmitted to the thin eardrum centrally, without a little buffering.

This stimulates the nerve endings, causes abnormal excitement of the auditory nerve, is prone to auditory fatigue, and the auditory nerves do not get a good rest, resulting in hearing loss or even loss.

Moreover, many young people often use mobile phones and other devices to listen to music when the volume is higher than the safety level, such as the use of headphones on noisy subways or buses, will always unconsciously increase the volume, but also hurt hearing.

02. Which headphones hurt your hearing the most?

The study found that different types of headphones do have different levels of hearing hazards. Whether the headset provides a buffer area for sound is the key to the headphones affecting hearing.

Among our common flat-headed, in-ear, and over-ear headphones, in-ear headphones have the greatest damage to hearing.

Flat-head headphones: Worn at the outer ear canal opening, a sponge is usually applied to the head of the headset.

In-ear headphones: Also known as earbuds, on the basis of ordinary headphones, the rubber plug head is inserted into the ear canal to obtain better airtightness.

Headset: that is, worn on the head, the channel mouth of the outer ear is tightly plugged by the headset, almost in a closed state.

The length of the human ear canal is 2.5 to 3.5cm, and when we use headphones, the resonant sound wave frequency is between 2500Hz and 3300Hz.

◆ In-ear headphones

Due to the complete obstruction of the ear canal, a relatively closed chamber is formed, and the resonant sound wave frequency is increased to between 4000 and 5000 Hz, and the sound waves in this frequency band are greatly enhanced. It is also this band that becomes the invisible killer of irreversible hearing damage.

In addition, because the colloid plug head almost completely blocks the external ear canal, the sound has no provenance, and the sound is almost entirely received by the eardrum, which is more damaging to the hearing.

◆ Headphones

Compared with the sound wave reflection space of in-ear headphones, the pressure on the eardrum is relatively small, so the damage to the hearing is smaller than that of the ear, but due to the better closure, under the condition of the same volume, most of the energy is still received by the eardrum, and the hearing loss is still large.

◆ Flat head headphones

Because it is located outside the external auditory canal, the sound conduction distance is longer, the closure is lower, the high-frequency part of the sound is more absorbed by the air, and the energy output of the sound source to the eardrum is lower than that of the first two headphones, which is the least damage to hearing.

03. Won't bone conduction headphones damage hearing?

In recent years, bone conduction headphones have gradually entered the public eye and become new Internet celebrity headphones. Some merchants said in the promotion that "bone conduction headphones use the principle of bone conduction to transmit sound, and under any circumstances will not damage hearing." ”

Is this really the case?

First of all, we need to know that we have two ways of hearing, one is air conduction, and the other is bone conduction.

Air conduction is caused by the vibration of the medium in the air through the sound source, the vibration of the eardrum through the external ear canal, and then the sound is transmitted to the inner ear through the three listening ossicles of the vibrating middle ear.

In nature, 90% of us use air conduction for listening, which is how traditional headphones take advantage of this.

Bone conduction is the vibration of the skull caused by the conduction of sound, which directly causes the vibration of the lymphatic fluid in the inner ear, and the sound and electrical conversion is carried out by the hair cells in the inner ear and then perceived by humans.

Bone conduction headphones This is the use of this principle, in use can better avoid the shortcomings of traditional headphones, such as not having to plug the headphones into the ear, which can effectively avoid the invasion of bacteria, but also will not damage the ear canal. In addition, bone conduction headphones are open headphones that allow us to keep our ears open at all times.

But experts pointed out that whether it is bone conduction headphones or air conduction headphones, in the end, it is necessary to let the hair cells of the inner ear vibrate to cause hearing.

Therefore, no matter which kind of headphones you use, living or working in a noisy environment for a long time will still have hearing damage.

04. How to prevent hearing loss caused by wearing headphones?

Some otologists have suggested a simple way: wearing headphones should follow the "60-60" principle, that is, the volume of headphones should generally not exceed 60% of the maximum volume, and the continuous use of headphones should not exceed 60 minutes.

In addition, adults should not wear headphones for more than 3 to 4 hours a day, minors should not exceed 2 hours, and it is best not to listen to music for more than 40 minutes each time wearing headphones.

So, if you're wearing headphones at the moment, be sure to remember to master the volume and duration.