Diplophonia Explained

Above:	Diplophonia
Ipa Symbol:	V̬‼

Diplophonia, also known as diphthongia, is a phenomenon in which a voice is perceived as being produced with two concurrent pitches.^[1] Diplophonia is a result of vocal fold vibrations that are quasi-periodic in nature.^[2] It has been reported from old days, but there is no uniform interpretation of established mechanisms.^[3] It has been established that diplophonia can be caused by various vocal fold pathologies, such as vocal folds polyp, vocal fold nodule, recurrent laryngeal nerve paralysis or vestibular fold hypertrophy.^[4]

The Voice Quality Symbol for diplophonia is V̬‼.

References

1. Ward. Sanders. Goldman. Moore. 1969. Diplophonia. The Annals of Otology, Rhinology, and Laryngology. 78. 4 . 771–777 . 10.1177/000348946907800409 . 5799401 . 208953905 .
2. Kiritani. Hirose. Imagawa. 1993. High-speed digital image analysis of vocal cord vibration in diplophonia. Speech Communication. 13. 1–2 . 23–32 . 10.1016/0167-6393(93)90056-Q .
3. Web site: 二重声の成立機序に関する音響的側面について. 吉岡博英. 筑波大学. 2015-12-26. 1987. Japanese.
4. Web site: 仮声帯肥大. sickness-dictionary.jp. 2015-12-26. Japanese. https://web.archive.org/web/20160304081444/http://www.sickness-dictionary.jp/nosethroat/karisetaihidai.html. 2016-03-04. dead.