Unconscious voice changes can give away true deep emotions.


As my boyfriend and I were having a casual dinner at a quiet Chinese restaurant, my boyfriend (who later became my husband) was telling me about his day when suddenly his voice unintentionally changed in a subtle way. It became a little scratchy, deeper and lower pitched when he said: “I really enjoy being with you” and as he reached for my hand “I’m falling in love with you.” The changing tone of voice touched me intensely. It sounded really genuine and true, coming from deep inside. It was charged with emotion. The words that were said were important but as important was the voice carrying those words.

One reason I was so touched and that I believed the sincerity in my boyfriend’s voice is that 30 years of practicing medicine had thought me to pay as much attention to the tone of voice in which patients spoke as to the verbal meaning of their speech. I had informally learned what social psychologists and psychoacoustics specialists have discovered in the laboratory, that “paralingual” (non-language) vocalizations carry an enormous amount of crucial information about a speaker’s true emotions. In particular, I had learned that when patients abruptly lowered the volume and pitch of their voice while adding “scratchiness,” they were going to tell me some deep, possibly scary truth about themselves.

Despite the importance of paralingual emotional content in verbal communication, Psychologist Paul Ekman has shown that we aren’t always aware of the emotions we transmit in our speech. Ekman called such unconscious expression of true emotions “leakage.” Jo-Anne Bachorowski of Vanderbilt University and Lolli et al at Wesleyan University have also found that we routinely make errors in judging the true emotions of others carried in vocalizations, especially if we are musically “tone deaf.” It turns out that people who are good at identifying emotions in human speech are often the same people who can carry a tune and correctly identify pitch in music, while, on average, people who can’t carry a tune and are hopeless at identifying the pitch of music are less able to determine emotion in speech.

But, can we learn to better recognize emotions in both our own speech and that of others, despite how tone deaf we might be, and can this improvement benefit our relationships?

The answer to both questions is a resounding “yes.” First, I’ll show how to pick up on verbal emotions, and then describe how to use this skill to improve relationships.

Better understanding paralingual vocalizations

The first and most surprising thing to understand about the emotional content of speech is that speakers don’t always inject emotion into what they say just to convey their emotions, but also unconsciously do it to influence your emotions.

Let’s go back to the change in my boyfriend’s tone of voice when he first said: “I really enjoy being with you.” He lowered the pitch (frequency) of his voice along with the volume (loudness) of his voice, while his voice got more “scratchy.” Anthropologists and evolutionary psychologists have found that human males do this when they want prospective mates to believe they are physically larger than average, by virtue of having a deeper voice. Whether true or not, Juan Leongomez of Sterling University says that we unconsciously believe that deeper voices go with larger bodies, which in turn have greater social dominance and survival value. Thus males, such as my boyfriend, unconsciously seek to increase their “mate-worthiness” by lowering the pitch of their voice.

The increased scratchiness of my boyfriend’s voice may also have been an unconscious expression of the anxiety he was feeling as he risked rejection by opening up and telling me for the first time that he loved me. Licia Sbattella and colleagues at Milan Polytechnic University in Italy found that when people experience fear the Harmonic to Noise Ratio (HNR) of their speech decreases, thereby increasing, among other types of “noise,” vocal scratchiness such as my boyfriend exhibited.

Women also unconsciously change their voices when they want to appear more “feminine” and sexually attractive to men, but women increase, instead of decrease the pitch of their speech. According to Greg Bryant at UCLA, women’s voices, for instance, unconsciously elevate in pitch when they are ovulating, apparently to increase the odds of capturing a suitable mate while they are most fertile.

All of these findings underscore a crucial aspect of understanding other people: A persona’s motivations, as well as their emotions, often “leak” into their speech and can be interpreted if you know what to listen for.

Now let’s talk about emotions themselves. Karl Scherer of the Affective Sciences Center at the University of Geneva has identified the physical properties of speech that typically convey different emotions. Scherer’s research characterized frequency (pitch) intensity (loudness) and variation in frequency (change from low to high pitch during vocalization), and articulation rate (rapidity of speech) to name just a few, Here are examples of physical speech characteristics of different emotions:

Stress: Increased intensity and frequency

Anger: Increased intensity and frequency, frequency variability, increased articulation rate

Fear: Increased intensity and frequency increase then decrease in frequency range, increased articulation rate

Sadness: Decreased intensity, frequency, frequency variability and articulation rate

Joy: Increased intensity and frequency, frequency variability, articulation rate

Boredom: Decreased frequency variability and articulation rate

Simply knowing these rules of thumb can help you better “read” people, even if you are tone deaf.

But there’s another way to improve your recognition of emotions in speech: close your eyes while listening.

Michael Kraus at Yale has shown that visual cues, such as facial expression, posture, and gestures distract us and actually degrade our ability to correctly read another’s true emotions. Experimental subjects who listened to videos of interactions between two people with their eyes closed, outperformed subjects who had their eyes open at identifying emotions of speakers in the videos. Kraus reached two conclusions from these findings: First, vocal channels of information carry more information about a person’s emotions than facial expressions, gestures, and posture, and second, we can improve our accuracy judging other people’s feelings by shutting out visual cues.

Using vocal cues of emotion to improve relationships

OK. So now that you know how to improve your understanding of another person’s emotions and motivations through their speech, how can you use this understanding to improve relationships?

Let’s start with the beginning of a relationship. Your brain is hardwired to prefer either lower or high pitched voices in the opposite sex (depending on your gender). If you find yourself falling for the “wrong” type of person, one reason could be that you unconsciously—but mistakenly—are making decisions based on “outdated” evolutionary information. Whereas reproductive fitness in prehistoric times might have been related to physical size and correspondingly low voice, for example, this is no longer the case in an era where knowledge and brains count for more than brawn. You can’t necessarily change how you initially feel about a person, based on the quality of their voice, but it may help to be aware that your feelings about someone you’ve just met may not be serving your best interests.

Another important way that better understanding emotions in speech can help relationships is to better understand your own emotions by paying closer attention to what you say.

Jean-Julien Aucouturiera and colleagues in France recently discovered that we make inferences about our own emotions from the quality of our own speech. Experimental subjects who listened to their own voices in earphones, where the verbal emotions were manipulated in real time by a computer, altered their emotions based on emotions that the computer artificially introduced into their speech. Incredibly, these subjects were unaware that the computer had been “messing with” their voices, and, in keeping with the James-Lang theory of emotions, took cues from their body (as opposed to their minds) to determine their own emotions!

This research implies that if you really want to know how you feel about someone, or something that they have done, listen carefully to the emotions not just in their voice, but in your own voice as well. You may well be “leaking” true feelings that you were not consciously aware of. Through my extensive work with couples over the years, I have learned that husbands and wives often suppress their true emotions to avoid unpleasantness and conflict (such suppression can be very harmful to both the relationship and the couple’s physical health), but those true feelings often “leak out” in their voices.

Here’s the bottom line: Clear communication is incredibly important to healthy relationships, especially communication of emotions. But we are not automatically good at understanding both other people’s emotions or our own in speech. So a good way to improve relationships is to pay much closer attention to the non-linguistic signals transmitted in other people’s voice and your own voice.

So next time you find yourself in an important dialogue, listen with one ear to the emotions in the other person’s voice, and with the other ear, to your own voice.

Sound advice for sound relationships!