Following is the full transcript of voice expert Rébecca Kleinberger’s presentation talk: Why You Don’t Like the Sound of Your Own Voice at TED Talk conference.
Rébecca Kleinberger – Voice expert
If you ask evolutionary biologists when did humans become humans, some of them will say that, well, at some point we started standing on our feet, became biped and became the masters of our environment. Others will say that because our brain started growing much bigger, that we were able to have much more complex cognitive processes. And others might argue that it’s because we developed language that allowed us to evolve as a species.
Descent of the larynx
Interestingly, those three phenomena are all connected. We are not sure how or in which order, but they are all linked with the change of shape of a little bone in the back of your neck that changed the angle between our head and our body. That means we were able to stand upright but also for our brain to evolve in the back and for our voice box to grow from seven centimeters for primates to 11 and up to 17 centimeters for humans. And this is called the descent of the larynx.
And the larynx is the site of your voice. When baby humans are born today, their larynx is not descended yet. That only happens at about three months old. So, metaphorically, each of us here has relived the evolution of our whole species.
And talking about babies, when you were starting to develop in your mother’s womb, the first sensation that you had coming from the outside world, at only three weeks old, when you were about the size of a shrimp, were through the tactile sensation coming from the vibrations of your mother’s voice.
So, as we can see, the human voice is quite meaningful and important at the level of the species, at the level of the society — this is how we communicate and create bonds, and at the personal and interpersonal levels — with our voice, we share much more than words and data, we share basically who we are. And our voice is indistinguishable from how other people see us. It is a mask that we wear in society.
But our relationship with our own voice is far from obvious. We rarely use our voice for ourselves; we use it as a gift to give to others. It is how we touch each other. It’s a dialectical grooming.
But what do we think about our own voice? So please raise your hand if you don’t like the sound of your voice when you hear it on a recording machine. Yeah, thank you, indeed, most people report not liking the sound of their voice recording.
So what does that mean? Let’s try to understand that in the next 10 minutes. I’m a researcher at the MIT Media Lab, part of the Opera of the Future group, and my research focuses on the relationship people have with their own voice and with the voices of others. I study what we can learn from listening to voices, from the various fields, from neurology to biology, cognitive sciences, linguistics.
In our group we create tools and experiences to help people gain a better applied understanding of their voice in order to reduce the biases, to become better listeners, to create more healthy relationships or just to understand themselves better. And this really has to come with a holistic approach on the voice. Because, think about all the applications and implications that the voice may have, as we discover more about it.
Your voice is a very complex phenomenon. It requires a synchronization of more than 100 muscles in your body. And by listening to the voice, we can understand possible failures of what happens inside. For example: listening to very specific types of turbulences and nonlinearity of the voice can help predict very early stages of Parkinson’s, just through a phone call. Listening to the breathness of the voice can help detect heart disease.
And we also know that the changes of tempo inside individual words is a very good marker of depression. Your voice is also very linked with your hormone levels. Third parties listening to female voices were able to very accurately place the speaker on their menstrual cycle. Just with acoustic information. And now with technology listening to us all the time, Alexa from Amazon Echo might be able to predict if you’re pregnant even before you know it.
So think about the ethical application of that. Your voice is also very linked to how you create relationships. You have a different voice for every person you talk to. If I take a little snippet of your voice and I analyze it, I can know whether you’re talking to your mother, to your brother, your friend or your boss. We can also use, as a predictor, the vocal posture. Meaning, how you decide to place your voice when you talk to someone.
And you vocal posture, when you talk to your spouse, can help predict not only if, but also when you will divorce. So there is a lot to learn from listening to voices. And I believe this has to start with understanding that we have more than one voice. So, I’m going to talk about three voices that most of us posses, in a model of what I call the mask.
So when you look at the mask, what you see is a projection of a character. Let’s call that your outward voice. This is also the most classic way to think about the voice, it’s a way of projecting yourself in the world. The mechanism for this projection is well understood. Your lungs contract your diaphragm and that creates a self-sustained vibration of your vocal fold, that creates a sound.
And then the way you open and close the cavities in your mouth, your vocal tract is going to transform the sound. So everyone has the same mechanism. But voices are quite unique. It’s because very subtle differences in size, physiology, in hormone levels are going to make very subtle differences in your outward voice. And your brain is very good at picking up those subtle differences from other people’s outward voices.
In our lab, we are working on teaching machines to understand those subtle differences. And we use deep learning to create a real-time speaker identification system to help raise awareness on the use of the shared vocal space — so who talks and who never talks during meetings — to increase group intelligence. And one of the difficulties with that is that your voice is also not static. We already said that it changes with every person you talk to but it also changes generally throughout your life.