Sendōon wa, jitsu wa masatsuon no isshu de aru. Kūki ga kōkō no ichikyōsakumon o tsūka suru sai ni, kyokubu ni ichijirushii sendō o shōzuru ni yotte hassuru on de aru. Ragyōon ga kore ni zokusuru. Sunawachi ragyōon wa, seitai no sendō ni nari taru koe ga, ken'yōsui o shigeki shite, kore o shindō shi, ichi no sen'on o shōzuru no de aru. Kono sen'on ga, sara ni zettō to kōgai to no kyōsakumon ni masatsu serarete, ragyōon wa naritatsu mono de aru.Trills are actually a type of fricatives. They are caused by significant vibrations at places of articulation where air passes through a constriction in the oral cavity. The sounds of the ra-row are trills. Specifically for the ra-row, phonation starts with vibrations at the vocal folds, then stimulates the uvula and shakes it, making a vibrating sound. This sound further undergoes friction at the constriction formed by the blade of the tongue and the palate, resulting in a sound of the ra-row.
