Loudness Is a Delivery Choice, Not a Fixed Trait
By Mira Lindqvist · Voice & Pace
"I'm just a quiet person" is one of the most common things a speaker says to explain low vocal energy on stage. It treats loudness as an identity. The acoustic research treats it as something else: an effort level, adjusted moment to moment, applied to the same instrument every speaker already has.
What changes when a voice gets louder
In a 2000 study, Hartmut Traunmüller and Anders Eriksson asked men, women and seven-year-old children to say the same sentence to a listener standing at distances ranging from 0.3 to 187.5 meters.1 As the distance grew, far more changed than volume. The sound level rose, and so did the balance of energy toward the higher frequencies. Vowels got longer. Pitch went up. The shape of the vowels themselves shifted.
The researchers defined vocal effort by asking a separate group of listeners to estimate, from each recording alone, how far away the addressee had been. Most of the acoustic changes tracked those estimates more closely than the actual distance. Listeners, in other words, can hear effort, not just loudness.
That is why a projected voice sounds different from a quiet voice with the microphone turned up. Amplification raises the level. Projection changes the whole sound, and audiences can tell the difference.
Where the power comes from
Ingo Titze and Johan Sundberg studied how vocal intensity is produced, comparing five professional tenors with twenty-five people without vocal training.2 Their models showed sound level rising by roughly 8 to 9 decibels each time the excess of lung pressure over the minimum needed to make the vocal folds vibrate doubled. Pitch contributed too: raised by an octave, with pressure raised to match, the voice gained a similar amount.
The comparison between groups is the part worth holding on to. At the same excess pressure, the trained tenors produced 10 to 12 decibels more intensity than the untrained men, mainly because more air flowed through the vocal folds at that pressure. The difference was in how the voice was used, not in a fixed property of the person.
Loudness, on this account, is mostly breath pressure and technique. Both can be trained.
Audiences read loudness as confidence
The level of a voice is not only about being heard at the back. In a set of experiments, Alex Van Zant and Jonah Berger looked at what people do with their voices when they try to persuade, and what that does to listeners.3 Speakers trying to persuade tended to speak louder and to vary their volume more. Listeners heard those changes as confidence, and that perceived confidence made the message more persuasive, without making the speaker seem less sincere. The effect held even when listeners could tell the speaker was trying to persuade them.
So a voice that stays quiet and even does more than make you hard to hear. It can make you sound less sure of what you are saying.
Habit versus limit
None of this says every speaker should be loud all the time. A talk with no dynamic range has a problem of its own, and the same is true of pitch, as covered in what monotone actually costs. Variation in volume was part of what Van Zant and Berger's listeners responded to, not just the average.
The useful distinction is between a habit and a limit. Most people's conversational volume is a habit set by the rooms they usually talk in: a desk, a café, a video call. Treating that resting level as a ceiling confuses where you usually are with where you can go. The research is specific that the gap between the two is mostly effort and breath, not anatomy.
How the Coach hears it
Exprea's Coach does not score how loud you are in absolute terms, because it can't know. A laptop microphone, a headset and the distance between you and either of them all change the recorded level, and none of that can be corrected for from a recording. What it measures instead is how much your level moves. It takes the level of each second of speech in decibels and looks at the spread. A spread of about 1.5 decibels or less scores in the poor band, and 5 or more in the good band. The limits of the measurement are set out in vocal energy.
Find the room you have
Test the gap. Read the same sentence at your normal conversational volume, then again as if to someone at the back of a large hall. The second version is still recognizably your voice, with more behind it. That gap is the range you have to work with.
Push from the breath, not the throat. Louder speech comes from more air pressure. Take a fuller breath before a phrase you want to carry, and let the sound ride on it. Squeezing from the throat tires the voice quickly and sounds strained.
Aim at a person at the back. Choose someone in the last row, or imagine one, and speak to them. Effort adjusts naturally to a target distance, which is exactly the variable Traunmüller and Eriksson manipulated.
Use volume to mark what matters. Lift your level for a key claim and drop it for an aside. Contrast does more than a constant high volume.
Practice at full volume before the day. Many people have never heard their own voice projected, and the first time it happens in front of an audience it can feel alarming. Rehearsing out loud, at the level you will use, removes that surprise.
Projection is a skill built like any physical skill: practiced deliberately rather than discovered as a personality trait. Most speakers use far less of their voice than they physically can.
References
- Traunmüller, H., & Eriksson, A. (2000). Acoustic effects of variation in vocal effort by men, women, and children. The Journal of the Acoustical Society of America, 107(6), 3438–3451. https://doi.org/10.1121/1.429414
- Titze, I. R., & Sundberg, J. (1992). Vocal intensity in speakers and singers. The Journal of the Acoustical Society of America, 91(5), 2936–2946. https://doi.org/10.1121/1.402929
- Van Zant, A. B., & Berger, J. (2020). How the voice persuades. Journal of Personality and Social Psychology, 118(4), 661–682. https://doi.org/10.1037/pspi0000193
Go deeper: What is pitch variation?