<unk> , also known as diphthongia, is a phenomenon in which a voice is perceived as being produced with two concurrent pitches.<unk>  is a result of vocal fold vibrations that are quasi-periodic in nature. It has been reported from old days, but there is no uniform interpretation of established mechanisms. It has been established that<unk>  can be caused by various vocal fold pathologies, such as vocal folds polyp, vocal fold nodule, recurrent laryngeal nerve paralysis or vestibular fold hypertrophy. The Voice Quality Symbol for<unk>  is V̬‼.
Diplophonia
Misophonia
Dyslexia
Dysmetria
Hypophonia
Abnormal posturing
Copropraxia
Dyskinesia