Voters are more likely to "elect" candidates with deeper voices regardless of the speaker’s gender, according to a new study. 

Previous studies have found that voters also preferred taller, more physically attractive and impressive candidates, and the latest research once again confirms suggestions that biology as well as partisanship and ideology, can effectively shape voters’ choices, according to Duke University researchers.

"We often make snap judgments about candidates without full knowledge of their policies or positions. These findings might help explain why," said Duke University biologist Rindy Anderson in a news release. She said that the latest findings could also explain why historically fewer women are elected to high-level political positions.

Researchers said that candidates typically know this, and they have been using vocal coaches to enhance their electability, but the current research scientifically confirms folk wisdom that the structure of the human voice matters.

The research team played two different digitally manipulated examples of the phrase “I urge you to vote for me this November,” to participants.  A set of participants listened to male voices and another group to female voices. 

The participants, consisting of both male and female, consistently preferred the lower-pitched voice, even among two women. 

Researchers said that the latest voice experiment stemmed from previous studies on the way visual cues affect people's perceptions of candidates and their competence and that voice pitch can also affect an individual’s perception of a speaker’s competence, honesty and strength.

Researchers also found that both men and women felt like lower-pitched female voices seemed stronger and more trustworthy and competent, but only male participants perceived lower-pitched male voices to be stronger and more competent. 

Researchers explain that male participants may have been more tuned into the voice pitch to gauge the speaker’s competitiveness and social aggressiveness, compared to female participants who may not discriminate strength and competence based on male voices because they are focusing on other cues, not pitch, to evaluate those traits.

Researchers noted that the findings are based on hypothetical elections conducted in a controlled laboratory setting, and needs to be confirmed by future research in order to apply it to broader real-world politics.

"We need to be very careful about interpreting these results in a broader context," Anderson said.

However, Anderson and her team plan to test their laboratory findings in the coming 2012 elections, and other future elections.

The findings were published in Proceedings of the Royal Society B on Wednesday.