To listen to audio clips from the study, go to tinyurl.com/atyc6yo.
The way you pronounce the letter "S" contributes largely to listeners' perception of whether you're male or female, according to new research from the University of Colorado.
Lal Zimman presented his research at the annual meeting of the Linguistic Society of America in Boston. His findings are based on research he conducted while earning his doctoral degree from CU's linguistics department.
Zimman studied transgender people transitioning from female to male and found that a person's style of speech can affect the perception of whether it's a male or female voice.
In sound samples, two transgender men say the same sentence. Both speakers' voices have an average pitch of 140 Hertz, which is typically considered to be part of the male-sounding vocal range. But they pronounce the letter "S" differently -- leading a group of listeners to unanimously perceive one to be male and another to be female.
Zimman, who said he's been involved in the transgender community as an activist, was curious as to what factors aside from testosterone lower the voice and affect how a person's gender is perceived. The participants in his study were treated with testosterone.
Even those with a higher-pitched voice could be perceived as male if they pronounced "S" in a lower frequency. That can be done by moving the tongue farther away from the teeth while talking.
"Children start to take on the voice traits associated with their gender from a really early age, as young as 4 years old," Zimman said. "People tend to look toward socialization early in life for causing a gender difference in voice."
Vocal resonance also affects a listener's perception of gender. Resonance is lower for people whose larynx is deeper in their throats, but children learn to manipulate that at an early age -- with boys pulling their larynxes down a bit and girls pushing them up, Zimman said.
Zimman, for his research, recorded the voices of 15 transgender men and used software to determine the frequency of the "S" sounds his subjects made. He digitally manipulated the recordings of the voices to be able to pinpoint how low each person's voice needed to drop before the majority of listeners identified the speaker as male.
The Wenner-Gren Foundation largely funded Zimman's research, which is being reviewed for publication.
CU associate professor Kira Hall, who served as Zimman's doctoral adviser, said a high-frequency "S" has long been stereotypically associated with women's speech, as well as the speech of gay men.
"The project illustrates the socio-biological complexity of pitch: the designation of a voice as more masculine or more feminine is importantly influenced by other ideologically charged speech traits that are socially, not biologically, driven," she said in a news release.
Contact Camera Staff Writer Brittany Anas at 303-473-1132 or firstname.lastname@example.org.