Headphones and hearing damage
Many teenagers do not pay attention to the protection of hearing, at a young age there are serious hearing problems, which must attract the attention of society as a whole. The biggest factor affecting the hearing of teenagers is the improper use of headphones, as shown in the long time, the volume of the first use of headphones, this bad habit has a serious threat to hearing, and can even lead to deafness in serious cases.
Many teenagers like to play online games, in order to pursue the sound, play with headphones, a bubble in front of the computer is a whole day or even all night, but also the volume of the headphones to the maximum; more people like to hang MP3, MP4, whether walking, sitting in the car or doing things, are listening to music, and feel that this is a very fashionable thing. Some people even accompanied by music into the face, after falling asleep music in the ears overnight. These bad habits accumulate over time and lead to tinnitus symptoms in many people, and some people have started to experience hearing loss.
Many people have misconceptions about hearing damage, thinking that hearing loss is a condition that occurs only in the elderly and has nothing to do with young people, so they do not pay attention to hearing protection and go to the doctor only when tinnitus or even hearing loss occurs, which is already a little late.
Scientists have found that the maximum intensity of sound that human hearing can withstand is 90 decibels. Experiments have shown that long-term exposure to sound stimulation above 105 decibels can cause permanent auditory damage. Many MP3, MP4 on the market, the maximum volume of up to 120 decibels, equivalent to the volume of the ambulance siren. Long-term, loud use of these devices will inevitably damage hearing, and over time, the auditory nerve cells of the inner ear will be severely damaged, possibly leading to permanent hearing loss.
How can we minimize the damage to hearing from headphones?
First, we need to understand the effects of different types of headphones on the eardrum.
Types of headphones.
Currently, there are three types of headphones: in-ear (plug-in), over-ear (close-fitting) and headband (full-coverage).
To understand why different types of headphones have slightly different effects on hearing, it is important to first understand the structure of the ear and the pathways through which sound is transmitted.
The structure of the ear
The ear is made up of the locus coeruleus and the auditory organ, both of which have different functions but are closely related structurally. The ear is divided into three parts: the outer ear, the middle ear, and the inner ear.
The outer ear has a prominent ear chakra that collects sound waves and transmits them along the ear canal to the eardrum. The tympanic membrane is a thin, tense layer of cotton paper the size of the fingernail of a small finger. The sound waves of ordinary conversation can cause the eardrum to vibrate very slightly, a vibration that is difficult to see even through a microscope, but is the key to the world of sound.
The middle ear is a small chamber between the eardrum and the inner ear, about half an inch long and a quarter of an inch wide, filled with air and connected to the nasal canal by the eustachian tube, thus keeping the chamber in balance with atmospheric pressure. The chamber has three small auditory bones (hammer bone, anvil bone and stirrup bone) linked in a chain from the tympanic membrane to the inner ear to transmit the tremors of the tympanic membrane. These three small bones are cleverly linked together to form a ring, which receives vibrations from the tympanic membrane and amplifies the sound waves 22 times before they are transmitted to the inner ear by a small membrane called the “oval window” (to which the stapes is attached), and after a series of complex procedures, the sound is then transmitted from the inner ear to the auditory center of the brain, and we hear the sound coming into the inner ear. In addition to the airborne pathway mentioned earlier, there is also a pathway of bone conduction, which simply means that sound waves are transmitted to the inner ear through the vibration of the skull to produce sound.
Studies have shown that earbud headphones are the most damaging to the sense of hearing.
The length of the outer ear canal is only 2.5~3.5 cm, and when earbud headphones are inserted into the outer ear canal, it creates a rather narrow “resonance box”. Much greater, so the degree of damage to the hearing is also much greater.
In order to obtain the same effect as headphones, headphone engineers use the natural structure of the human external ear canal to form a resonance chamber in order to enhance the sound quality. For example, in order to pursue strong low-frequency effects, in-ear headphones use a long flute type anti-sound leakage design, and the shape of the earbuds designed to fit the shape of the external ear canal, so that the earbuds and the external ear canal close, the direct use of the external ear canal as a bass resonance chamber, so that we can hear a more powerful bass effect.
In terms of process, this is certainly a clever design, but the damage to the sense of hearing is quite serious. Short-term use, because the human body has a considerable repair function, mildly damaged hearing can be recovered in time, the user will not feel the obvious hearing damage, but if the hearing in 2 to 8 weeks can not naturally recover, it may develop into permanent hearing loss, so if you use such headphones for a long time, it will undoubtedly make the risk of hearing damage.
Hearing impairment is a slow process, unlike visual blurring which causes immediate and significant discomfort to the patient, and minor hearing loss often goes unnoticed at first (no one takes a hearing test seriously as a routine medical checkup). Over time, when tinnitus appears and hearing loss becomes noticeable, patients realize its severity, but it is often too late by then.
Some studies have shown that noise stimulation causes hearing damage at 4000 Hz in the first place, with some damage in other high-frequency sound domains. In addition, even non-noise sound sources can cause cochlear damage and thus hearing loss if the volume is consistently too high. The reason for this may be that the cochlea is subjected to long-term excessive acoustic stimulation that produces metabolic disorders in tissue cells and damage to end receptors.
Since the human speech frequency is between 500 and 2000 Hz, hearing damage beyond this frequency is often not perceived by the patient, so people with hearing loss in the non-speech frequency area often do not perceive their hearing impairment and therefore do not change their lifestyle, much less seek medical attention, which makes the situation worse and misses the best time for treatment.
Due to environmental constraints, people in many cases will rely on earbud headphones to receive information (answering the phone, listening to the radio, listening to music, listening to foreign languages), if you pay a little attention, you will find that 70 ~ 80% of the passengers on the subway are looking down and fiddling with their cell phones, and at least half of them wear earbud headphones.
Our society is still in the development stage, as headphones are generally more expensive, many people also have to choose relatively cheap earbud headphones, and some manufacturers in order to meet consumer preferences, but also deliberately launched the so-called “special bass” earbud headphones, these factors will increase the risk of auditory damage.
In contrast, headphones are much less damaging to the hearing than earbud headphones, and their sound field and wearing comfort are better. These headphones create a near-closed audio environment by wrapping around the outer ear, and the sound area is farther away from the ear canal, so it causes less hearing damage than earbud headphones.
For the general public, just because of the possibility of hearing damage wearing headphones to give up the Walkman, smart phones and other devices to enjoy music is unrealistic, but at least we can give up the use of earbud headphones and use a lower degree of hearing damage headphones, which is a generation of Europeans to the painful lessons learned from experience. You know, with the current level of medicine, it is very difficult to recover after hearing damage.
Over-ear headphones
Hanging ear headphones refers to the side of the headphones added to the auxiliary hanging decoration to facilitate the use of a class of headphones, its advantage is both small size of earbud headphones, easy to carry and other advantages, but also because the headphones are not plugged into the external ear canal and reduce the damage to the hearing, but also because the designers in the production of ear hooks used aluminum alloy and with metal brushed technology, so ear hanging headphones often have a stylish shape, loved by young consumers. Its ear hook design also makes it easy to wear while exercising, suitable for people who listen to music while working out. But it also has obvious disadvantages, one is the sound leakage, the second is not suitable for people wearing glasses to wear. However, from the point of view of avoiding damage to the hearing, sound leakage is in fact exactly where the advantages of hanging ear headphones. On-ear headphones can not be as close to the external ear canal as earbud headphones, this structure will cause sound leakage, but it is precisely the leakage that reduces the direct stimulation of the eardrum, thus reducing the damage to the hearing.
Therefore, the choice of headphones should be a balanced consideration, sound quality, sound effects, of course, but the long-term auditory health also need to take into account.
In any case, the following principles need to be kept in mind by every frequent user of headphones.
1, do not wear headphones for a long time, every half an hour to let the ear rest, adults wear headphones for a maximum of 3 hours a day, teenagers should not exceed 2 hours, and to intermittent use is appropriate. Everyone’s sensitivity to noise is different, about 5% of the population is susceptible to noise.
2, the volume should not be opened too much, if a person standing 1 meter away to give you a speech you can not hear clearly, then you should reduce the volume.
3, headphones to choose the volume can be adjusted, the volume control at 80 decibels or less, to feel comfortable sound pleasant to the ear. 85 decibels is the highest limit of the national noise protection standards, more than 85 decibels is noise.
4, do not listen to headphones while sleeping, if you sleep with headphones on one side of the ear pressed against the pillow, will increase the stimulation of sound waves on the eardrum and thus aggravate the ear injury.
5, it is best to use headphones, because this kind of headphones on the auditory damage is less than embedded headphones.