Controlling the brightness of the voice

A few weeks ago I posted about “Sexy baby voice,” the topic of a chapter in Lake Bell’s audiobook about the culture and politics of voices. Bell identified three characteristics of “sexy baby voice” in women: high pitch, “vocal fry” (creaky voice) and “slurring.”

In phonetics, “pitch” is generally understood to refer to the fundamental frequency of the speech signal, but on Twitter the phonetician Byron Ahn posted the results of a computer analysis of some of the examples Bell gave for “high pitch” and pointed out that their fundamental frequencies weren’t much higher than the examples she gave for “normal” speech. In my post, I suggested that Bell is probably referring to the frequencies of harmonics in the speech, also called “resonance” or “formants.” It sounds like the most salient feature of “sexy baby voice” is bright resonance.

As I discussed in my post, bright resonance is generally associated with youth and femininity, because it’s usually caused by small vocal folds in small vocal tracts, and women and children tend to be smaller and have smaller vocal folds. Even younger women tend to have brighter resonance than older women, primarily because of the affect of hormonal changes during childbirth and menopause.

Of course, as Bell demonstrates repeatedly in her chapter, bright resonance can also be controlled, either consciously in the moment or subconsciously through habit and training. I’ve learned about these ways over the years, as a linguistics doctoral student, as a transgender woman and as an amateur singer. I’ll go through all the ways I know to do this.

Diagram of the vocal tract produced by the U.S. Centers for Disease Control and Prevention, and distributed by Wikimedia Commons.

As with the previous post in this series, my knowledge comes from training, not reading, so I don’t know who to credit for figuring all this out about the vocal tract. For now I will credit my primary teachers: the vocal coaches Kristy Bissell and Erin Carney, and the phoneticians Jacques Filliolet, Karen Landahl, Alex Francis and Doug Honorof.

For people who haven’t studied the anatomy of the vocal tract, this will get a little technical. In this blog post I’m going to use all the technical language, but if there’s a particular area that you feel could use more explanation for a general audience, please let me know.

Let’s start with the larynx and move through the vocal tract with the breath. The vocal folds generate sound through their vibration. When closing completely they generate a relatively coherent sound wave, but they can add dark resonance by maintaining gaps of particular sizes to allow low-frequency vibrations, what we call creaky voice or “vocal fry.” Similarly, they can add bright resonance by allowing turbulent air to flow through, causing breathy voice.

Just above the larynx is a tube called the pharynx. We can add bright resonance by constricting the pharynx, a practice that vocal coaches call “twang.” The name confused me for a while, because I associate the word “twang” with the Southern vowel shift, but in this case it refers to the narrowing of the pharynx.

The velum is a flap of muscle that we open to allow air to flow through the nose. When we allow air to flow through the nose and mouth at the same time it produces nasal resonance, which adds brighter resonance.

We use our tongues to produce consonants and vowels, raising a part of the tongue towards the roof of our mouths, so a /d/ sound is formed by touching the front of the mouth, and a /g/ sound by touching further back. For each of these sounds there is a range of positions along the roof of our mouth. When we raise our tongues further forward within the range for that sound, we generate brighter resonance. We can also generate bright resonance by flattening the tongue, allowing it to be raised higher. There is extensive research showing that women and gay men tend to have brighter resonance on their /s/ phonemes, and that people who make brighter /s/ sounds tend to be heard as women or gay men, even if they aren’t.

The lips are the gates that release our voices to the air outside. Rounded and protruded lips can produce darker resonance, and spread lips (in a smile or similar shape) can produce lighter resonance. I remember hearing about a study showing that even before puberty, boys tend to round their lips to sound more masculine.

One thing that makes this confusing is that all these vocal tract configurations have other functions. Creaky voice can be a sign of fatigue. Breathy voice can be a sign of relaxation. Pharyngeal constriction, nasal resonance, place of articulation and lip rounding can each change one word into another word with a completely different meaning, in Arabic, French, English and other languages.

These articulations can also interact with each other and with the fundamental frequency of the voice in different ways. At low frequencies, breathy voice can sound sympathetic or sexy, but at high frequencies it can sound weak and vulnerable. This may be what you want to project, or it may not. Nasal resonance and pharyngeal constriction can sound forced or strident, obnoxious or insensitive.

The bottom line is that these aspects of the voice are all under some degree of conscious control. How much control a speaker has, and how conscious they are, depends on a lot of factors, but the takeaway for Bell’s chapter is that people with smaller vocal tracts can use these techniques to speak with darker resonance than they would without them, and people with larger vocal tracts can use them to speak with brighter resonance than they otherwise would.

Note that I’m using the term “otherwise.” The terms I want to avoid, for this post at least, are “natural,” “authentic,” “real” and “your/my/their voice.” The tension between biological constraints, habit and conscious control is what makes resonance so fraught, politically, culturally and socially, which is why Bell and others have such intense feelings about it. That’s for another post.

2 thoughts on “Controlling the brightness of the voice

  1. Iago


    His article went through my timeline and I thought it was amazing.
    It is very difficult to find this theme being transmitted in an accessible way.

    I am a student of speech therapy in my country and would respectfully like to make a contribution to your text. It’s a small detail compared to the rest of the information that was provided in the text. Well, the soft palate, or velum, as well as the pharynx are composed of structures that are mostly muscular and not cartilaginous. The structure with some cartilaginous structure is the larynx.

    I want to say that now you have one more follower on twitter.
    Thank you so much!
    I apologize for my English from google translator and if in any way I was disrespectful

  2. Thank you, Iago! I wrote that bit a little too quickly, and I’ve now corrected it.

    E eu leio um pouco de Português, então você pode commentar na tua lengua se você quer!

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