Otocarti is the next generation of earphones with cartilage conduction, the third auditory pathway.

What is the difference?

The way of cartilage conduction transmits sound to the ear is completely different from the conventional airway (canal-type earphones) and bone conduction (bone conduction earphones).

*The third type of hearing by cartilage conduction was discovered in 2004 by Dr. Yuji Hosoi, Chairman and President of Nara Medical University.​

Sound is created by the “vibration” of a small sphere without holes.

Otocarti is resistant to failure and deterioration

Because Otocarti has no holes, there is no need to worry about sweat during exercise. The waterproof rating is IPX5, so there is no problem even if the device is exposed to water.

And there is no risk of dust or dirt entering through the holes and damaging the device.

The spherical shape is easy to clean and sanitize.

Sound leakage has been an issue with conventional bone-conduction earphones, but Otocarti is designed to prevent sound leakage.According to the results of a sound leakage experiment conducted by our company, Otocarti had about 15~20db less sound leakage compared to general bone conduction earphones.

Even when you are out and about, you can use Otocarti with peace of mind, free from worry about sound leakage.

The small spherical body is lightly placed against the cartilage of the ear so that it does not block the ear canal, resulting in less stress on the ear.

Conventional earphones case

Canal-type earphones (earplug type), which block the ear canals, can easily cause ear problems such as otitis media due to steam inside the ear canals after wearing them for a long time.

Bone conduction earphones case

Because the large vibrating body is pressed against the temples with strong pressure, prolonged tightening may cause pain.

No unpleasant vibrations like bone-conduction earphones

The Otocarti has a low vibration level, and hardly any uncomfortable vibrations are felt. Children can also use it with peace of mind.

The left and right sounds are not easily mixed, and you can enjoy the same stereo and realistic feeling as with conventional earphones. The new “stereo” sound quality is as if you are listening through speakers.

Because the ear canals are not blocked, the user can hear surrounding sounds.

This is the reason why Otocarti is called the earphone that combines the best of both “bone conduction” and “canal type”.

• LITE: Neckband type

Since they are worn around the neck, they are stable and comfortable to use, and there is no need to worry about glasses or hairstyle.

• ACTIVE: Headband type

Recommended for people who practice jogging and gym workout. No need to worry about sweat getting into the sound ball through the earphone holes. They can be easily wiped with a cloth, making them easy to clean.

Headband type earphones can be worn during strenuous exercise without worrying about the earphones falling out of the ears.

• MATE: Hearing amplifier

MATE is a set of cartilage conduction earphones and a hearing amplifier. 

By installing a high-performance chip specially designed for sound collectors, we have made particular efforts to ensure that speech is heard loudly.

Recommended for people who have hearing impairment due to aging

When you put on Otocarti MATE

Otocarti MATE is easy for anyone to use.

Otocarti combines the advantages of conventional earphones and bone-conduction earphones.

• Bluetooth type

• Hearing amplifier

• Simple and easy operation without Bluetooth/wireless functions​: Simple design for easy use even by those who are not good with digital devices. No special operation is required.
• Slide volume made in Japan for fine volume adjustment: Equipped with a slide potentiometer* made by a major Japanese manufacturer, the volume can be adjusted smoothly and independently for the left and right ear, so if you have difficulty hearing in one ear, you can increase the volume in only one ear. 

*What is a sliding potentiometer (Pot)?​: An adjustable voltage divider consisting of a resistive element and a sliding contact. Using only two terminals, one end of the element and the adjustable contact, it can operate as a variable resistor or rheostat.

• Unique equalization technology enhances voices: Most sound collectors amplify all sounds, which makes unwanted noises louder at the same time. This product uses a unique technology that eliminates unwanted noise, so you can hear voices louder.
• Attached neck strap eliminates the risk of losing the device. It can also be fastened to your clothes with a clip.
• Equipped with a high-capacity battery that can be used for 15 hours. Equipped with a battery that can be recharged repeatedly. No need to replace batteries. *The usage time may vary depending on the usage conditions.
• Anti-howling function​: Suppresses howling sound to reduce discomfort.

In mid-May 2022, I had the privilege of meeting Dr. Hosoi, the President of Nara Medical University, who is the discoverer of the third auditory pathway, cartilage conduction.

I was impressed by the discovery of cartilage conduction and its potential. Based on this experience, I decided to develop  “cartilage conduction earphones and hearing amplifier” that would be relatively inexpensive and easy to use, so I focused on this project and devoted myself to product development. As a result, the prototype “Otocarti” was completed in October 2022.

In November 2022, we challenged a crowdfunding project in Japan and succeeded in raising approximately 12,000,000 JPY, giving us firm confidence in the potential of this product.

Through the INDIEGOGO project, we hope that the existence of cartilage conduction and its potential will be recognized by many people around the world and reach the ears of those who need it.

CEO Ryo Higashi, TRA Co., LTD. ​

• About Cartilage Conduction Hosoi

• About Cheero

With the motto of “Your cheerful digital life”, we manufacture and sell convenient smart accessories, centering on power banks and audio products.

We work on product development while making daily improvements in order to provide simple, easy-to-use, and reasonably priced good products.

Risks & Challenges

• If mass production efficiency improves due to your support and purchase, there is a possibility that the regular selling price will be lower than the planned selling price.
• Since the product is still under development, there is a possibility that some specifications such as design, color, and material may be changed.
• Shipping may be delayed due to order status, availability of materials used, or manufacturing process reasons.

  *We do not accept returns or refunds for anything other than initial defects.

• The color of the image may appear different from the actual product depending on the monitor environment.