Voters in elections are more likely to pick candidates with a deeper voice, a new study has suggested.
Researchers at two US universities made recordings of both male and female speakers and then altered the pitch of their subjects' voices.
In the study,published in Proceedings of the Royal Society B, listeners "voted" more frequently for the "candidate" with the lower voice.
Researchers now want to test their findings in a real political situation.
Previous research has found that the pitch of a human voice can strongly influence how people are perceived.
This study looked at how it may affect the way we choose leaders.
Seventeen women and 10 men were recorded saying the phrase: "I urge you to vote for me this November."
Each of the recordings was then modified electronically, changing the pitch to create pairs - one higher and one lower than the original. Both were then played to the "voters" taking part in the study.
Researchers found that those listening to the recordings were more likely to vote for the candidate with the deeper voice regardless of whether the speaker was male or female.
One of the authors, Casey Klofstad from the Department of Political Science at the University if Miami said "Candidates already know about this and they have been using vocal coaches to enhance their electability and what we have done is proven the folk wisdom that the structure of the human voice matters and actually shown that scientifically."
A different study published last November also found a preference for lower voices. Rather than playing recordings of hypothetical candidates it used archive material of former US presidents.
Researchers say there is a chance that in the earlier work participants might have recognised the voices or based their choices on political preferences.
They believe this latest work also goes further because for the first time it used both male and female voices.
Rindy Anderson who worked on the research at Duke University in North Carolina said: "It's clear that our voices carry more information than the words we speak. Knowing this can help us understand the factors that influence our social interactions and possibly why there are fewer women elected to high-level political positions."
In another part of the study, researchers found that women with lower voices were perceived to be stronger, more trustworthy and competent.
Prof Sophie Scott, a specialist in human communications at UCL's Institute of Cognitive Neuroscience, told the BBC that both men and women deliberately choose to speak with particular pitches.
"What we're showing with our voices is what we consider to be an appropriate way of speaking and to show things about ourselves that we want other people to like about us or know about us.
"You can't treat the voice as some passive thing reflecting back very simplistic information about people."
The researchers behind this latest work now want to move beyond hypothetical elections in a laboratory and to test what they have found in real elections.