Alterations in Emotional Expression Through Speech in Patients With Unilateral Vocal Fold Paralysis: A Preliminary Study.

Unilateral vocal fold paralysis (UVFP) has a known impact on patients' quality of life. One of the potentially affected domains that has not been studied yet is emotional prosody. To produce and transmit an efficient emotional prosody, several vocal parameters are modulated by the speaker, principally the fundamental frequency, the speech rate, and the voice intensity. We retrieved 300 sentences produced by 10 patients suffering from UVFP, equally in neutral, anger, and sadness. A jury of six health care voice experts was asked to hear these sentences and choose an emotion for each vocalization, between neutral, anger, and sadness. The jury mainly considered the heard sentences as being in a neutral emotion. Vocal parameters analysis of the anger and sadness sentences that were mistaken as neutral showed the absence of significant difference in their fundamental frequencies and speech rates. By being unable to modulate their vocal parameters as needed to produce emotional prosody, specifically the fundamental frequency and speech rate, patients with UVFP suffer from limitations in their capacity to produce the emotional prosody wanted, making the emotions they feel hardly transmitted to their entourage, which can explain the social barriers these patients complain of.