Have you ever noticed that your best friends speak the same way? A new University of British Columbia study finds we prefer voices that are similar to our own because they convey a soothing sense of community and social belongingness.

While previous research has suggested that we prefer voices that sound like they are coming from smaller women or bigger men, the new study - published in the journal PLOS ONE - identifies a variety of other acoustic signals that we find appealing.

"The voice is an amazingly flexible tool that we use to construct our identity," says lead author Molly Babel, a professor in the Department of Linguistics. "Very few things in our voices are immutable, so we felt that our preferences had to be about more than a person's shape and size."

Aside from identifying the overwhelming allure of one's own regional dialects, the study finds key gender differences. It showed a preference for men who spoke with a shorter average word length, and for "larger" sounding male voices, a finding that supports previous research.

For females, there was also a strong preference for breathier voices- a la Marilyn Monroe - as opposed to the creakier voices of the Kardashians or Ellen Page. The allure of breathiness - which typically results from younger and thinner vocal cords - relates to our cultural obsession with youthfulness and health, the researchers say. A creaky voice might suggest a person has a cold, is tired or smokes regularly.

Babel says the findings indicate that our preference for voices aren't all about body size and finding a mate, it is also about fitting in to our social groups.

Background

Babel and her colleagues at the University of California, Santa Cruz asked college-aged participants in California to rate the attractiveness of male and female voices from people living west of the Mississippi River.

They found that participants preferred different acoustic signals for males and females - and the strongest predictors of voice preference are specific to the community that you're a part of.

For example, the Californian participants had a strong preference for female voices that pronounced the "oo" vowel sound from a word like "goose" further forward in the mouth. This has been a characteristic of California speech since at least the early 1980's. In many other regions of North America, people would pronounce the "oo" sound farther back in the mouth, as one might hear in the movie Fargo.

The preference for males who had shorter average word length relates to a difference between how men and women speak. In North American English, longer average word length is a style typically used by women while shorter average word length is one used by men. The preference for men with shorter average word length connects to what we consider normal or average.

Foreign accents

Given the anecdotal evidence of people's preference for foreign accents, Babel theorizes that at a certain point the exotic is also appealing. "Once you are outside of a certain range of familiarity, novel and exotic sounding voices might become more attractive," she says. "We also have to keep in mind that we find some accents more preferable than others because of social stereotypes that are associated with them."