In 1994, Rudolf P Gaudio, of Stanford University, published a paper called Sounding Gay: Pitch Properties in the Speech of Gay and Straight Men. Gaudio studied the speech sounds of (a) some openly gay white American men and (b) some openly straight white American men. Then he asked volunteers to listen and see if they could identify which was which. They could.
Janet Pierrehumbert and four colleagues looked at a very particular aspect of the question "What, technically, is the sound of gay male American speech?" They also examined the speech of lesbian and bisexual American women.
The team published a study called The Influence of Sexual Orientation on Vowel Production. Its summary is unapologetically technical. But for acousticians and linguists accustomed to reading dry reports, one passage sings with lilting clarity:
"Differences in the acoustic characteristics of vowels were found as a function of sexual orientation. Lesbian and bisexual women produced less fronted /u/ and /[open aye]/ vowel sounds than heterosexual women. Gay men produced a more expanded vowel space than heterosexual men. However, the vowels of gay, lesbian, bisexual speakers were not generally shifted toward vowel patterns typical of the opposite sex."