What is The Principle of Bone Conduction Headphones and Are They Safe?
As the name suggests, bone conduction headphones are headphones designed based on bone conduction technology.
Bone conduction is a sound conduction method. The vibration of the sound source drives the bone to vibrate, and then transmits the sound to the inner ear, so that the sound can be heard. It transmits sound without passing through the air and eardrum, which also enables the sound transmission way of bone conduction to clearly restore the sound in a noisy environment, and will not affect others due to the spread of sound waves in the air.The technology of bone conduction is very mature. In the 18th century, Beethoven used bone conduction technology to hear the sound of piano performance.
Bone conduction technology has a wide range of applications. It has been used more in the military field and hearing assistance field in the past. But in recent years, this technology has been widely used in bone conduction headphones, making this headphone a fashionable product and becoming popular.
What is the principle of bone conduction headphones?
Before understanding the principles of bone conduction headphones, we need to review our middle school physics to understand the three mediums for sound transmit: air, solids, and liquids. Air conduction is what we know most about, such as ordinary conversation is the case that sound transmit through air. When your place ear to the railway, and when a train comes in the distance, you can hear the sound, which is the case of sound transmission by solid. When we dive, we can hear the sound of the engine of a ship in the distance, which is the case of sound transmission by liquid.
Bone conduction headphones are a device that transmits sound through solid (bone) conduction. It transmits sound by vibrating your skull. This is unlike the air conduction of traditional wired and wireless headphones. Bone conduction headphones do not transmit sound through the eardrum, so even if the volume is slightly louder, it will not easily damage the eardrum.
We can compare the sound transmission paths of bone conduction and air conduction
Bone conduction pathways: sound waves, skull, bone labyrinth, inner ear lymph, spiral organ, auditory nerve, auditory center of the cerebral cortex
Air conduction pathways: sound waves, auricle, external auditory canal, periosteum, ossicles, vestibular window, internal and external lymph, spiral organ, auditory nerve, cerebral cortex auditory center
We can see that bone conduction has a shorter sound transmission path than air conduction, and that it takes a shortcut. And this shortcut helps bone conduction headphones not to be stuffed into the ear or wrapped around the ear. So the headphones will not cover the ear canals and have no damage to the eardrums, and the damage to the auditory nerve is relatively low.
After understanding the working principle of bone conduction headphones, we will know that they will not use eardrums when working, which is undoubtedly very safe for ears. Next, let’s learn about the safety of them.
How safe are bone conduction headphones?
Bone conduction headphones are a new application of mature technology, and their safety has early been verified.
First of all, bone conduction headphones have very little damage to hearing. We all know that hearing damage generally occurs in the eardrum and inner ear. When we wearing them,sound do not need to pass through the eardrum, so they do not damage the eardrum. Because the oscillation of them is relatively moderate, the headphones also have less effect on auditory hair cells in the inner ear. Moreover, the electromagnetic waves of them are extremely weak that they will not cause harm to human brain nerves and hearing nerves.
Secondly, bone conduction headphones can still keep you paying attention to ambient sounds when worn, which can help you to avoid many accidents. They are not worn into the ear, Whether in running, cycling, walking or commuting, etc., wearing the headphones to listen to songs, you can still hear the surrounding sounds, and can communicate with others normally, so as to avoid the danger caused by not hearing external sounds.
In addition, bone conduction headphones that do not need to be plugged in the ear canal when worn, are very helpful for maintaining ear hygiene. They do not block the ear canal due to sweating for a long time to deposit a large number of bacteria, and so also reduce ear inflammation and other conditions.
Of course, The safety of any product is relative, and 100% safe products do not exist, and so are bone conduction headphones. Under the premise of long-term continuous use at high volume, they still have the risk of hearing damage. This point also needs to be paid attention to when they are used. It should be noted that any headphones will have hearing damage problems when used at high volume for a long time. Bone conduction headphones are still the safest and healthiest of all headphones.
From the introduction above, you may be interested in bone conduction headphones. However, how to the headphones still needs careful consideration. Sound quality, sound leakage reduction and security are the three main issues you must consider. Next, I will recommend several mature bone conduction brands, hoping to help you select suitable headphones.
1.Wissonly Hi Runner bone conduction headphones
Reason for recommendation:
I noticed Wissonly bone conduction headphones when they were first crowdfunded online. And later, I saw that some otologists were recommending them on online forums, so I bought them. This Hi Runner is their flagship product whose overall functionality is also the most perfect. The headphone use the latest research from the Wissonly lab. It increases the vibrating area of the vibrator by 35% and optimizes the direction of sound transmission to make the sound more concentrated, resulting in a wider range and more spatial of the music. The brand claims that its sound quality is HI-FI level, and I actually tested it myself. I thought that the sound quality was very close to HI-FI level, but it did not reach this level. Of course, the current sound quality is satisfactory enough.
Wissonly bone conduction headphones are also equipped with a new Bluetooth 5.0 chip that has stronger anti-interference ability, that can easily cope with various complex outdoor scenes, and ensures the good mood during exercise is not disturbed by disconnection. At the same time, the stable connection also brings low latency performance, and there is no problem in listening to songs, following dramas, and playing games. What’s more, they have 32G of built-in memory that can store 5,000 songs. This helps you to enjoy music when you are exercising outdoors without your phone.
In terms of comfort, the Wissonly Hi Runnerperforms well, it is very light, only less than 30g, and it does not feel any weight to wear. The body is made of titanium alloy which makes it have a good fit, and you don’t need to worry about their falling off during sports.
The waterproof of the Wissonly Hi Runner deserves special mention, and it is IPX8 grade. It means that you can carry it underwater for up to 20 meters and still use it normally, which is crazy!
2. Philips A6606 bone conduction headphones
Reason for recommendation:
This Philips A6606 bone conduction headphones, with an ergonomic design, will not fall off no matter how you move. The surface of its body is made by soft silicone, which greatly improves the comfort of wearing. It has reached the IP67 waterproof rating, and sweating profusely during daily sports is not a problem to it. The headphones are also equipped with night running lights, and the brightness is strong enough that the cyclists or vehicles behind you can notice you when you are running at night. The headphones are equipped with Bluetooth 5.2 technology which has a faster transmission distance and lower power consumption than 5.0, but this one cannot be used in swimming.
3.AfterShokz OPENRUN PRO bone conduction headphones
Reason for recommendation:
Openrun PRO also pays great attention to comfort in wearing, and its body is made of skin-friendly silicone which makes it more comfortable, and it can be better enjoyed. In order to reduce the weight, titanium alloy is selected in its connection material, which is not easy to bend and deform, ensuring the service life. The bone conduction headphones are also equipped with Qualcomm QCC3024 chip and Bluetooth 5.0, and have stable connection and no disconnection in daily use.
4.earsopen SS900 bone conduction headphones
Reason for recommendation:
It adopts the 5.2 Bluetooth protocol, which can start automatic connection when the charging compartment cover is opened. It is low latency during use, and the anti-interference ability is also strengthened. In terms of sound quality, BoCo’s miniature bone conduction vibrator is adopted, which has good performance at low frequencies, but which has harsh noise and serious sound leakage at high frequencies. The 8G single-earphone body is basically comfortable during the whole wearing process.
5.Nank Runner CC3 bone conduction headphones
Reason for recommendation:
Runner CC 2 bone conduction headphones adopt a combination of soft and hard to reduce sound leakage. The entire headphones adopt a seamless design, even the headset mic is wrapped in silicone. The unique sound leakage cancellation technology can greatly reduce the leakage phenomenon.
It uses magnetic charging, after each use, you only need to put the magnetic tip in the buckle position of the headphones. Compared to traditional headphones, Runner CC2 bone conduction headphones has no holes in the entire body, and it has a certain waterproof effect.
It is generally a good entry-level bone conduction headphone. But the waterproof level is not enough, it is are not suitable rain or water sports.
The five bone conduction headphones described above performed well in terms of sound quality, safety and comfort. Among them, Wissonly and Aftershokz are the two brands with strong technology accumulation in the field of bone conduction, and the product quality will be better, which are most worthy of recommendation. Considering the cost performance ratio, Wissonly will be better.