According to recent media reports, a 20-year-old young man has been wearing bone conduction headphones while exercising for a long time, repeatedly troubled by tinnitus, and finally diagnosed with noise induced hearing loss. This is not an isolated case. In hospital clinics, hearing loss caused by the use of headphones is more common than people have heard. Data shows that noise induced hearing loss has become one of the three major factors leading to hearing loss, and people who are inseparable from headphones for a long time are at high risk. Today we will learn about the healthy relationship between headphones and hearing, as well as how to use headphones correctly. The "sacrifice" of auditory hair cells is irreversible noise deafness, which refers to progressive sensorineural hearing loss caused by long-term exposure to harmful noise environment. The incidence rate is only second to senile hearing loss. What is the volume considered noise? The volume of daily conversations is about 60 decibels, which will not damage hearing. When the volume exceeds 80 decibels and is exposed to this environment for more than 40 hours per week, it may cause irreversible damage to hearing. As the volume increases, the safe exposure time decreases sharply. For example, a weekly safe exposure time of 90 decibels is about 4 hours, while a weekly safe exposure time of 100 decibels is less than 20 minutes. According to the exposure method, noise induced hearing loss can be divided into two categories. Exposure to strong noise (such as loud explosions or sudden headphone sounds) in the short term may cause acute injury. Instantaneous strong noise (exceeding 120 decibels) can impact the eardrum and cochlea, leading to acute necrosis of hair cells. Long term exposure to high noise environments such as textile factories and airports, or long-term improper use of headphones, can lead to cumulative hearing loss. There are about 15000 auditory hair cells in the inner ear cochlea, which are the "sensors" of sound and responsible for converting sound waves into EEG signals. So, how does noise kill these hair cells? Mechanical damage caused by strong sound waves hitting the inner ear can cause the cilia of hair cells to collapse, cell connections to be disrupted, and even the basement membrane to tear, leading to the mixing of internal and external lymphatic fluids and resulting in toxic death of hair cells. Metabolic damage and strong noise can cause inner ear vascular spasm, leading to microcirculatory disorders and metabolic disorders in hair cells due to ischemia and hypoxia. The large amount of free radicals generated by oxidative stress can sustainably damage the cochlea for 7 to 10 days, which means that even without a noisy environment, inner ear damage may still progress. The cruelest thing is that mammalian hair cells do not have the ability to regenerate. Once the damage reaches a critical point, hearing loss becomes permanent. It should be clarified that clinically defined deafness is not "completely inaudible". When the hearing loss exceeds 25 decibels, it is judged as deafness. If there is no sign of recovery after a stable decline in hearing for more than 6 months, this damage is usually difficult to reverse. In recent years, research has found that hearing recovery after noise exposure does not necessarily mean that the auditory system is safe and sound. The "signal lines" (i.e., ribbon synapses) connecting hair cells and auditory nerves may have been damaged, leading to "hearing but not hearing clearly". In addition, noise may also induce endolymphatic edema, which is the core pathological feature of Meniere's disease, manifested as paroxysmal vertigo, fluctuating hearing loss, tinnitus, and ear stuffiness. Meanwhile, noise induced microcirculatory disorders in the inner ear can further exacerbate tinnitus symptoms, forming a vicious cycle of "hearing loss tinnitus". Earphones are not guilty, the key is how to use them. Currently, there are three types of mainstream headphones with the highest usage rate on the market. 1. In ear/head mounted headphones have good sound insulation and rich sound quality details, but blocking the ear canal can easily breed bacteria, and excessive volume can stimulate the inner ear more strongly. 2. Bone conduction headphones do not block the ears, have high comfort, can maintain perception of the surrounding environment, and are safer during exercise. But in noisy environments, users unconsciously increase the volume to a dangerous level in order to hear the content played by the headphones clearly. 3. Noise cancelling headphones can reduce external noise, so users do not have high requirements for headphone volume. But the price of these headphones is relatively high, and some people may feel uncomfortable with "high ear pressure". From the characteristics of the above three types of headphones, noise cancelling headphones are preferred for commuting and taking the subway, bone conduction headphones can be selected for sports, and in ear or head mounted headphones are suitable for office and study. As for whether headphones will damage hearing, the question is not which type of headphones to choose, but how to use headphones correctly. Taking the bone conduction earphone mentioned in the previous news as an example, its working principle is to directly transmit the vibration of sound waves to the cochlea through the skull, bypassing the external auditory canal and eardrum. Although these headphones do not block the ear canal and can prevent bacterial growth, whether sound is transmitted through air or bone, it is ultimately received by the hair cells in the inner ear. If the volume is too high, strong vibrations can directly impact the skull and transmit to the inner ear, which can also cause sensorineural damage. That is to say, as long as it is headphones, there is a risk of excessive use. Whether it is a healthy person or a patient with hearing loss, the core of protecting hearing is to control the volume and duration. Control the ambient volume as much as possible to keep the noise level below 80 decibels. Judgment method: If it is necessary to raise the voice in order for someone within arm's reach to hear the conversation clearly, it indicates that the environmental noise has exceeded the standard. Following the principle of "60-60-60", the volume should not exceed 60% of the maximum volume of the device, the headphone volume should not exceed 60 decibels, and the time spent wearing headphones should not exceed 60 minutes per day. Proper protection is necessary when exposed to noisy environments for extended periods of time. It is recommended to use professional noise cancelling earplugs, which can reduce noise exposure by 5-45 decibels when worn correctly. In addition to headphones, there are many high noise scenes in daily life that are easily overlooked, such as KTV, bars, and game halls (95-110 decibels); Gym spinning and exercise classes (85-100 decibels); Long term phone calls, hands-free (70-90 decibels), etc. In these environments, people should try to shorten their stay time or use noise cancelling earplugs. Three symptoms indicate that the ear is in distress. Noise induced hearing loss usually progresses slowly, and early symptoms are often easily overlooked. When the following symptoms appear, it indicates that the ear is "calling for help". High frequency hearing loss makes it difficult to hear distant high notes, such as bird calls or phone ringing; When talking to others, I always feel that they have "unclear speech" (especially unable to distinguish consonants such as "s", "sh", "f"); I feel like the familiar music has changed tone. When persistent tinnitus is quiet, there is a continuous sound of cicadas chirping, electric currents, or rustling in the ears. This situation will be temporarily masked in noisy environments, but becomes more pronounced after quietness. Hearing allergies and ear stuffiness can be harsh to daily sounds such as the collision of dishes and the sound of doors closing; The ears seem to be blocked by cotton, with a vague feeling of 'separated by a membrane'. Self testing for hearing problems can be done by placing a mechanical watch or mobile phone's second hand sound close to your ear. If you cannot hear the "ticking" sound at a normal distance, it may indicate that high-frequency hearing has been damaged (this method is for preliminary self-examination reference only and cannot replace professional examination). If symptoms such as high-frequency hearing loss, persistent tinnitus, auditory hypersensitivity, and ear tightness occur, especially if tinnitus lasts for more than 24 hours, contact with noise should be immediately stopped and a pure tone audiometry examination should be performed at the hospital's otolaryngology department as soon as possible. For sudden or acute hearing loss, 72 hours after onset is the golden window for treatment. At this time, most hearing impairments are still in the stage of cellular edema and microcirculation disorders, and timely intervention may be salvageable. If you miss 72 hours, it is also recommended to actively receive treatment within a month, as there is still a possibility of improving hearing. Once hearing loss exceeds six months, intervention often has little effect. At present, the clinical treatment mainly adopts a comprehensive treatment plan: glucocorticoids (anti-inflammatory and anti-inflammatory), microcirculation improving drugs (such as Ginkgo biloba extract), and hyperbaric oxygen therapy. If irreversible hearing loss has occurred, individuals with moderate to severe hearing loss can be fitted with hearing aids. For extremely severe patients, cochlear implants may be considered. Moreover, when these individuals re-enter noisy environments, they must wear professional noise cancelling earplugs or earmuffs to prevent further deterioration of their hearing. Four major misconceptions about hearing loss in extended reading: Misconception 1: Rest for a while. After hair cells are injured in a strong noise environment, they may experience tinnitus, ear tightness, and temporary hearing loss, which can be restored after rest. However, long-term and repeated exposure to strong noise without recovery from auditory fatigue can cause degeneration and necrosis of hair cells, making them unable to regenerate. So, we must not take it lightly just because we can recover. Misconception 2: Only "inability to hear" is considered deafness. In addition to being unable to hear, the inability to hear high-frequency sounds (such as bird calls and doorbell sounds) is also an early manifestation of deafness, as high-frequency hearing is quietly losing. Misconception 3: Young people are not afraid of "making", but the opposite is true. Young people wearing headphones at high volume for a long time can cause more severe hearing damage than age-related deafness. Senile hearing loss is a slow decline in hearing, while noise induced hearing loss is the forced destruction of hearing. The World Health Organization warns that over 1 billion young people worldwide are at risk of hearing loss due to unsafe listening methods. Misconception 4: Putting some cotton in the ear can reduce noise. Ordinary cotton has almost no sound insulation effect on high-frequency noise. It is necessary to use professional noise proof earplugs, wear them correctly, and seal the ear canal to effectively isolate injuries. The ear is one of the most delicate organs in the human body, and those hair cells are fragile and non renewable, but noise induced hearing loss can be prevented. Starting today, people who rely on headphones should always remember to lower the volume when using them, take regular breaks, and pay attention to every faint cry for help from their ears. (New Society)