When George H.W. Bush ran for president in 1988, he hired a voice coach to help him lower his voice an octave. Why? Because the candidate’s high-pitched voice had helped saddle him with the “wimp” image, even though Bush had proved his valor as a Navy combat pilot during World War II.
Fairly or unfairly, we impute strength and confidence to the person who speaks with a low-pitched, well-modulated voice.