Kuchi shōga (口唱歌), also known as 'kuchi showa' and 'kuchi shoka', is a Japanese system for 'pronouncing' the sounds of drums, especially Japanese drums (taiko).
For example, a deep, sustained sound from the center of the drum might be rendered as "don" and a sharp tap on the side would be "ka". "Tsu" represents a lightly struck note, and "su" represents a pause.
The system is used for recording, teaching, and memorization of drum rhythms. It is also used for 'subtitles' in drumming video games like Taiko no tatsujin.
External links
Taiko.com article
DrumDojo.com page