顫動音

顫動 (“vibration”) +‎ 音 (“sound”)

• (Tokyo) せんど​ーおん [sèńdóꜜòòǹ] (Nakadaka – [3])
• IPA^(key): [sẽ̞ndo̞ːõ̞ɴ]

顫(せん)動(どう)音(おん) • (sendōon) 

1. (phonetics) Synonym of 震え音 (furueon, “trill”)
   • 1902, Hirano, Hidekichi, “第一節　　父音の分類 [Section 1: Types of Consonants]”, in 國語聲音學 [The Phonetics of the National Language], 國光社, pages 78–79:

     顫動音は、實は摩擦音の一種である。空氣が口腔の一狹窄門を通過する際に、局部に著しい顫動を生ずるによつて發する音である。ラ行音が之に屬する。卽ちラ行音は、聲帶の顫動に成りたる聲が、懸壅垂を刺戟して、之を振動し、一の顫音を生ずるのである。此顫音が、更に舌頭と口蓋との狹窄門に摩擦せられて、ラ行音は成り立つものである。

     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.