Human voice

The human voice is the sound made by a human being using the vocal tract. This includes things like talking, singing, laughing, crying, screaming, shouting, humming, and yelling. The main part that makes these sounds is the vocal folds, often called vocal cords, in our throats.

To make voice sounds, three main parts work together: the lungs, the larynx (or voice box), and the articulators. The lungs push air up to make the vocal folds vibrate, creating sound. The muscles in the larynx change the shape of the vocal folds to adjust the pitch and tone of the voice. Then, the articulators—like the tongue, palate, cheek, and lips—shape and fine-tune the sound as it comes out.

Our voice is very powerful. We can use it to show emotions such as happiness or sadness. It can also tell others about our age. For singers, the voice becomes a musical instrument that helps create beautiful music.

Voice types and the folds (cords) themselves

Main articles: Vocal folds and Voice types

Men's and women's voices often sound different because their vocal folds, also called vocal cords, are different sizes. Men's vocal folds are usually longer, which makes their voices sound lower. Women's vocal folds are shorter, so their voices usually sound higher.

These folds are found in the larynx, or voice box. They are attached at the back and front to different parts of the larynx. When the inner edges of these folds vibrate, they create sound. Because of these size differences, men's and women's voices have different pitches and tones. Voices can be grouped into types, like bass, tenor, alto, and soprano, based on their range and quality.

Voice modulation in spoken language

When we speak, most people can change how their voice sounds. The two biggest things we change are how high or low our voice sounds (called pitch) and how close together our voice parts (vocal folds) are.

Our bodies change how close these voice parts are very quickly. This helps keep food from going into our lungs when we swallow. Even young children learn to change their voice this way when they start talking.

Sometimes, when these voice parts move far apart, the voice stops making sound. We call these sounds "voiceless." But even when the voice doesn’t completely stop, the way the voice changes helps us understand these sounds. Special sounds like "glottal stops" happen when the voice parts come together, even if the voice doesn’t fully stop.

Physiology and vocal timbre

Everyone's voice sounds different because of the shape and size of their vocal cords and body. Our voices change with how tight or loose our vocal cords are, and how we use our breath. The shape of our chest, neck, tongue, and even muscles can change how we sound.

Singers can learn to make their voices sound better by using special techniques called vocal resonance. The larynx, or voice box, helps us make different sounds. This is why singers can use different vocal registers, which are ways of making sound with the same vibration pattern of the vocal cords. These registers help create different pitches and tones.

Influences of the human voice

Main articles: Voice projection and Evolution

The twelve-tone musical scale, used in much of today’s music, might have started from the way people naturally sound when they speak. A study in 2021 found that the sounds people make match the notes in this musical scale. This shows how our voices may have helped shape music over time.

Voice disorders

Main articles: Vocal loading and Voice disorders

Many things can change how we use our voices. Some people might find it hard to speak clearly, or they might get small growths or injuries on the parts of the body that help us speak, called vocal folds. Talking or shouting for long periods can stress these important parts.

If someone has trouble with their voice, a special doctor called an ENT might help. The best way to keep your voice healthy is to use it carefully. A person trained to help with speech, called a speech-language pathologist, can also show you how to improve your voice.

Vocal cord nodules and polyps

Vocal nodules happen when we use our voices too roughly over time. This can create soft, swollen spots on the vocal cords. If this keeps happening, the spots can grow bigger and become harder.

Polyps are usually larger and can happen from one rough use of the voice. Sometimes they need surgery to remove them.

If you feel hoarse or your voice sounds breathy for more than two weeks, it’s best to see a doctor. Speech therapists can help teach ways to use your voice better and avoid these problems.