[Column] Risks and avoidance measures for noise-induced hearing loss that many modern people have | BARKS

▲ LOOP What is LOOP and how is it epoch-making? It is the point that the change in sound quality (sound muffled) that occurs with volume suppression is solved by imitating the physical structure of the ear canal. The human ear is connected to the eardrum through an elongated hole of 25 mm to 30 mm called the ear canal, but because it has a tubular shape with only one side open, it causes air column resonance called open tube resonance. It is a physical phenomenon in which a peak (high level) and a dip (low level) occur at a natural frequency by blowing a bottle to make a sound. However, it seems that the brain makes corrections under consciousness and subtracts that amount. There is no way to know the fact that large peaks occur at approximately 3kHz and 9kHz in daily life. However, if you close the hole with earplugs, the physical characteristics of the ear will change completely from open-tube resonance to closed-tube resonance. In other words, since the specific frequency of the resonance deviates greatly, the peak and dip of the open tube resonance that had been unknowingly corrected up to now suddenly disappear, and instead, the peak and dip appear in a different frequency band due to the closed tube resonance. Perhaps the brain is confused with "Eh? Eh?". LOOP uses ear tips with high sound insulation to capture external sound from the opening while ensuring quietness, but before flowing it into the ear canal, it passes through a hollow channel that imitates the ear canal. In other words, after generating the same peak and dip as the original open tube resonance, the sound is delivered to the eardrum. This is the basic mechanism for recognizing the same sound as the original tone. I'm worried about the new peaks and dips generated by the closed tube resonance, but since the sound in the outer ear is a low volume with sound insulation of 20db, the closed tube resonance generated from there is minimal and all are masked. It will end up. It is inevitable that LOOP has a tubular structure, but by shaping it as compactly as possible with 3D printing technology, it will be designed to fit all ears, and it will be compact and fashion like pierced earrings. It became an item with sex. It's designed so that it doesn't pop out of your ears, so you can use it without problems even when you sleep. When you get LOOP and use it in various scenes, you can feel that the sound itself is very clear and has a natural tone without stagnation, while it is light and comfortable to wear and has solid sound insulation performance. Forgetting even the fact that it is attached is largely due to the "naturalness of sound quality" as well as the "good fit". This is the decisive difference from general earplugs. Because it is not completely sound-insulated, you can enjoy music and conversation without any discomfort, and you will not miss life alerts. Not only at live venues, but also at engine sounds, work sounds such as power tools, pachinko halls, karaoke, movie theaters, etc., you can get a safe and secure sound suppression environment that is different from usual. I don't want to. Freed from noise, even when traveling by air or by train, creates a very peaceful environment, and silence is justice when you want to improve your concentration. It's just earplugs, but with the quietness and peace of mind that you can get with this one, you can get a high-quality daily life as if your life level was raised by one rank. The "quiet environment" can be said to be the "best luxury item" for busy modern people.Sentence: BARKS Editor-in-Chief Tetsuya Karasuma ● LOOP 3,880 yen (tax included) on sale ・ Hearing protection earplugs designed for concerts, events, sports, travel and musicians ・ Size: 1.5 cm in diameter ・ Weight: 2 g ・ Material : ABS resin ・ Accessories: Pouch, user guide, 6 sets of ear tips (memory foam: size S, M, L, silicon ear tips: size S, M, L) ・ Color variations: Swinging Silver / Raving Red / Midnight Black / Glorias Gold / Fuller Tea Rose Gold ◆ LOOP Official Site

* Mechanism of noise-induced hearing loss

Many hair cells of different lengths stand side by side in the cochlea, each of which is responsible for each frequency. A loud sound is a strong stimulus for hair cells, and if the stimulus is continued, it will collapse like fatigue. When you are young, you can recover by resting and start up again, but that is also a problem, and if you do not recover while lying down, you will not be able to hear only that frequency range. This is the process of developing noise-induced hearing loss. The danger of noise-induced hearing loss changes not only with the volume but also with the load time. Even if it is not so big, the risk increases if the exposure time is long. On the contrary, when it comes to a loud volume of 120 dB, 7 minutes is the limit. Noise-induced hearing loss is often damaged from 4KHz and 6KHz, and then the inaudible area expands from 3KHz to 2KHz. Not only noise-induced hearing loss but also presbycusis due to aging does not damage the hair cells in the entire area at once, so it is difficult to notice the fact that a specific frequency cannot be heard. By the time you realize that "something has become hard to hear ...", you are in a state of "already late" when a great deal of damage has spread. There is also "difficulty in ear care". Even in total darkness, as time goes by, "the eyes get used to it" and the surroundings become vaguely visible, which is dark adaptation in which the dynamic range of vision is changed by the work of the brain. The phenomenon of "I don't feel it when it's big" occurs. In that state, the music doesn't feel powerful, and it goes into a spiral of raising the volume, and eventually it becomes a situation where "I don't realize that I'm exposed to a loud volume that damages the auditory cells." Even at the concert, the volume is getting louder and louder in the second half, but many spectators are unaware of it. The solution to this problem is simple: "rest your ears". Stop the music and take a break in 10 minutes. If you reset the sensitivity of your ears and prepare earphones / headphones with high sound insulation, you can receive the abundant amount of information that music has at a very low volume. If you increase the sensitivity of your hearing and widen your dynamic range, you will be able to fully enjoy music even at a low volume, so it is the most effective defense measure to be aware of protecting your ears from a loud volume even in daily life. Will be.Tweet this article Audio & Musical Instruments