Why Some People's Voices Change When They Talk To You

It's an all-too-familiar cinematic and TV trope — a guy is joking around with his buddies, his voice at a normal pitch, when suddenly the phone rings. He picks it up, and suddenly he's all "Hey, how you doin?" a full octave lower. You just know the caller is a) female and b) pretty. Or else there's a woman who, surrounded by friends or family, may be cackling like a hen or squealing like a stepped-on guinea pig, but as soon as she picks up the phone she's purring like a kitten. There's even the pre-caller ID variant where she answers the phone in full-on sultry siren mode, then finds out it's not who she was expecting. Her resigned sigh of "oh, it's you, Egbert" reverts right back to her normal tone. (Apologies to any Egberts out there — this name was undoubtedly the epitome of sexy in the pre-Norman Conquest era.)

Whether or not the people on the other end of the phone ever catch on, we in the audience have known since Clara Bow starred in her first talkie that this change in tone signals how the person answering the phone "like likes" the caller. As with so much else that resides in the realm of common sense, science has weighed in and told us that — surprise — what we've suspected all along is actually true. Wow, thank you, science. What's next, you'll prove that night is darker than day and donuts taste better than broccoli?

What voice changes may signify

A 2010 study published in the Journal of Nonverbal Behavior (via Springer) found that people of both sexes tend to lower the pitch of their voices to a greater extent the more attractive they perceive their conversational partner to be. One of the study's authors, Dr. Susan Hughes, characterized this oh-so-useful information as being potentially "adaptive for identifying interested potential mates," but then went on to drizzle a little rain on that parade by adding that it could also be useful for "detecting partner interest in others, and... partner infidelity."

Inc. notes that if someone's voice changes when they're talking to you, it doesn't necessarily signify interest in hooking up. It could just be that the person you're talking to you is interested in your idea, and the pitch drop may be a "tell" that you've just closed the deal on whatever you're selling. Still good news, if not quite as flattering.

The Journal of Phonetics (via Science Direct) also brings up yet another reason behind vocal changes. A 2012 study showed that people in close proximity (such as college roommates) often adopt each other's voice patterns. This is a phenomenon called "phonetic convergence" and the more convergence, the greater the degree of closeness, but this study did indicate that the whole voice-changing thing can happen when you're just friends. So again, not necessarily a romantic thing, unless you're starring in a romcom, of course. In that case, happily ever after is but a montage away.