The Imperial Japanese Army was a Japanese military force that existed from the Meiji era to the Showa era.

The Imperial Japanese Navy was once the navy of Japan.

Infrasound is a type of sound that is inaudible to the human ear.

Debuccalization refers to the phenomenon in phonetics where a specific sound is pronounced outside the oral cavity.

Kunminjōon is a book for teaching the correct pronunciation of Hangul.

The Japanese Society for Rights of Authors, Composers and Publishers is an organization that protects the copyrights of musicians.

Understanding the concept of 'Ha-line conversion sounds' is important in learning Japanese.