Diplophonia, also known as diphthongia, is a phenomenon in which a voice is perceived as being produced with two concurrent pitches. Diplophonia 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 diplophonia can be caused by various vocal fold pathologies, such as
vocal folds
In humans, vocal cords, also known as vocal folds or voice reeds, are folds of throat tissues that are key in creating sounds through vocalization. The size of vocal cords affects the pitch of voice. Open when breathing and vibrating for speech ...
polyp,
vocal fold nodule
Vocal cord nodules are bilaterally symmetrical benign white masses that form at the midpoint of the vocal folds. Although diagnosis involves a physical examination of the head and neck, as well as perceptual voice measures, visualization of the v ...
,
recurrent laryngeal nerve
The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve ( cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and ...
paralysis
or
vestibular fold
The vestibular fold (ventricular fold, superior or false vocal cord) is one of two thick folds of mucous membrane, each enclosing a narrow band of fibrous tissue, the vestibular ligament, which is attached in front to the angle of the thyroid car ...
hypertrophy.
The
Voice Quality Symbol
Voice Quality Symbols (VoQS) are a set of phonetic symbols used to transcribe disordered speech for what in speech pathology is known as "voice quality". This phrase is usually synonymous with phonation in phonetics, but in speech pathology encom ...
for diplophonia is V̬‼.
References
Respiratory diseases
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