Disorders of the voice can affect a politician's success

The acoustics of a political speech delivery are known to be a powerful influencer of voter preferences, perhaps giving some credence to the saying, "It's not what you say, but how you say it." Vocal disorders change the qualities of a person's speech, and voice scientists Rosario Signorello and Didier Demolin at the Université Sorbonne Nouvelle, Paris have found that this alters politicians' perceived charisma and listeners' voting preferences.

The researchers examined two cases of politicians with vocal disorders: Umberto Bossi, former leader of the Italian Lega Nord party, whose vocal cords were partially paralyzed by a stroke, and Luiz Inácio Lula da Silva, former president of Brazil, whose larynx has disturbed functionality due to throat cancer. Signorello will present the findings at the 174th Meeting of the Acoustical Society of America, being held Dec. 4-8, 2017, in New Orleans, Louisiana.

In both vocal pathologies, the vocal range was narrowed and pitch lowered. The disordered voices were characterized by hoarseness, a slower speech rate and a restriction in the ability to modulate pitch. "We use pitch manipulation to be ironic and sarcastic, to change the meaning of a sentence," said Signorello, emphasizing the limited speech capabilities of the politicians after their pathology.

"Before the stroke, people perceived Bossi as positive, enthusiastic, a very charming speaker, and when listening to his post-stroke voice, everything changed," said Signorello. "After the stroke, he had a flat pitch contour, a lack of modulation, and this was perceived as a wise and competent charisma."

Multiple charismatic adjectives were assessed on a Likert scale of agreement by a French audience. Using an audience who didn't understand the languages of the vocal stimuli was important. "[W]henever you listen to a voice you assess the acoustics, but also what they say, and we didn't want the verbal, semantic content to influence our results," said Signorello.

The French listeners were asked which vocal stimuli they would vote for and, perhaps surprisingly, there was a preference for the leaders' post-disorder voices. "French people didn't want to vote for someone who was strong and authoritarian, or perceived as a younger version of the leader," said Signorello. However, this was a variable trend. "In each example the vocal patterns are so diverse you never find the same answers; all trigger different emotional states and convey different personality traits."

Emphasizing that there is no "best" voice, Signorello said, "Charisma is a social phenomenon, difficult to assess because it is subject to social trends. It's impossible to give a recipe of what is more or less charismatic—it's like fashion, it changes drastically with time."

The researchers found it intriguing that the leadership charismas identified from post-vocal disorder vocal stimuli were characterized by personality traits that are also used to describe an older person, for example, as wise. "We are interested in how age and the perception of age from voice influences the social status of a speaker in a given society," said Signorello, who plans to investigate this further.

He plans to extend the study to vocal disorders of female politicians, aiming to use the findings to improve and focus speech rehabilitation of public speakers, from teachers, to CEOs and politicians. He is also interested in applying these findings to smart device voice recognition technology.