KYOTO -- A Kyoto Prefecture-based company has developed earphones covered in pure gold and adorned with diamonds that can send sound through one's ear cartilage.

The company behind the jewelrylike earbuds is CCH Sound Inc. in the prefectural town of Seika, a venture firm that develops devices utilizing the "cartilage conduction" mechanism, where sound is transmitted through vibrations in the cartilage near the ear.

Cartilage conduction differs from conventional air conduction, where sound travels through air vibrations, passing through the eardrum from the outside. Instead, vibrations in the cartilage generate sound within the external auditory canal, which then reaches the eardrum, passes through the middle ear and cochlea, and is recognized as sound by the brain. This mechanism was discovered in 2004 by Nara Medical University President Hiroshi Hosoi.

In recent years, cartilage conduction earphones have been commercialized and are gaining attention. Unlike traditional earbuds, they do not have holes that function as audio output and do not need to be inserted into the ear canal, allowing users to engage in conversations while listening to music.

Cartilage conduction can also make sound easier to hear for those with hearing difficulties including elderly individuals. As a result, sound amplifiers connected with small spherical cartilage conduction earphones are gradually being introduced in government offices, hospitals and other locations.

The small vibrator component of CCH Sound's new spherical earphones is encased in pure gold and decorated with diamonds. Each earphone contains 9 grams of pure gold, and diamonds of at least VS2 clarity are used.

A company representative commented, "Because these earphones do not have audio output holes, they can have a shape like fine jewelry, resulting in a beautiful finish. Through this, we aim to spread awareness of cartilage conduction across Japan and the world."

The gold earphones will be shown at the Great Golden Exhibition in Osaka this March.

(Japanese original by Satoshi Kubo, Kyoto Bureau)