Stroboscopy also can give an incorrect impression when the vocal folds are producing more than one periodic source, as in some cases of diplophonia
Vocal fold cysts may cause hoarseness, breathiness, pitch instability, diplophonia
, and compensatory hyperfunction.
, meaning "double voice," refers to a phenomenon in which two (or more) pitches are sounded simultaneously.
The physical examination was notable for a raspy voice with obvious diplophonia
and mild inspiratory stridor.
On examination, the patient was moderately breathy and hoarse, and she experienced occasional episodes of diplophonia
, especially at the higher frequencies.
Voice may also have a bitonality or diplophonia
, with the perception of two different fundamental frequencies (or pitches) simultaneously.