You better watch the tone you take with that stranger. Scientists have found if a person's voice goes deeper when they are talking to a person they find attractive, they are more likely to cheat. l Bosque University psychology researchers write for The Conversation about a study in which participant were played recordings of people speaking and given no other background information about them. Most were able to choose which voices belonged to cheaters, and women were better at it than men. For now, we don't know the cues the participants used to judge whether the voices came from cheaters, but it could have to do with pitch.
Women's voices are known to change during her menstrual cycle when she is not using contraceptive pills. Men find women's voices most attractive when the woman is near ovulation (most fertile), compared to other times of the month. Another study found, when talking to attractive people, men's voices tended to go deeper, and both men and women increased how varied their pitch was when around attractive people. The researchers write, "Practically speaking, picking up on these types of cues could allow someone to decide whether a person they are talking to might be attracted to them or not."