How voice is produced: phonation, articulation and resonance
- Mechanism
- For completeness
Air from the lungs makes the vocal folds vibrate; the throat, mouth and nose shape that buzz into speech.
Also called: Phonation, Speech production, Vocal fold vibration
See it in 3D: Vocal folds · Thyroid cartilage · Epiglottis · Recurrent laryngeal nerves · Trachea
What it is
Voice needs three things: a power source (exhaled air), a vibrator (the vocal folds in the larynx) and shapers (resonating cavities and articulators). The folds are brought together and set into vibration by airflow; their tension, length and mass set the pitch. The pharynx, mouth, nose and sinuses resonate, while lips, tongue and soft palate shape vowels and consonants.
How it works, step by step
- Adductor muscles (lateral cricoarytenoid, interarytenoids) bring the vocal folds together.
- Expiratory muscles raise subglottic pressure until it pushes the folds apart and a puff of air escapes.
- Tissue elasticity and the drop in pressure in the fast-moving air (Bernoulli effect) pull the folds back together.
- This cycle repeats many times per second, producing a buzzing tone (fundamental frequency).
- Cricothyroid tilts the thyroid cartilage forward, lengthening and tensing the folds: pitch rises.
- Thyroarytenoid (vocalis) shortens and thickens the folds, lowering pitch and adjusting quality.
- The vocal tract filters the tone: resonances (formants) set vowel quality; articulators add consonants.
Typical speaking fundamental frequency (approximate)
| Parameter | Value |
|---|---|
| Adult man | ≈ 85–155 Hz |
| Adult woman | ≈ 165–255 Hz |
| Child | ≈ 250–300 Hz or more |
Approximate values for a healthy adult at rest; each laboratory sets its own ranges.
Intrinsic laryngeal muscles and voice
| Muscle | Action | Nerve |
|---|---|---|
| Cricothyroid | Lengthens and tenses folds (raises pitch) | Superior laryngeal (external branch) |
| Posterior cricoarytenoid | Abducts folds (opens glottis) | Recurrent laryngeal |
| Lateral cricoarytenoid | Adducts folds | Recurrent laryngeal |
| Interarytenoids | Close the posterior glottis | Recurrent laryngeal |
| Thyroarytenoid (vocalis) | Shortens and relaxes folds; fine control | Recurrent laryngeal |
Clinical notes
- Hoarseness after thyroid or chest surgery suggests injury to the recurrent laryngeal nerve; the left nerve, looping under the aortic arch, is more exposed.
- Vocal fold nodules from voice overuse add mass and stop the folds from closing fully: rough, breathy voice.
- Puberty enlarges the male larynx and lengthens the folds, which lowers the voice by about an octave.
Test yourself
Think of the answer, then tap the question to see it.
Which muscle raises the pitch of the voice, and which nerve supplies it?
The cricothyroid, by lengthening and tensing the vocal folds; it is supplied by the external branch of the superior laryngeal nerve.
What is the only muscle that opens the glottis?
The posterior cricoarytenoid, supplied by the recurrent laryngeal nerve.
What brings the vibrating vocal folds back together after each puff of air?
Their elastic recoil and the fall in pressure in the fast airflow between them (Bernoulli effect).
Why does the left recurrent laryngeal nerve cause hoarseness more often than the right?
It has a longer course, looping under the aortic arch, so chest disease and surgery can injure it as well as neck surgery.
Connections
See it in 3D5
The structures of Durgical's 3D anatomy where it happens.
Educational physiology content; not a diagnostic or treatment guide and no substitute for a health professional's advice. Values are approximate references. No doses are given.
Sources: Anatomy, Head and Neck, Larynx Vocal Cords (StatPearls (NCBI Bookshelf), 2025); Anatomy, Head and Neck: Larynx Muscles (StatPearls (NCBI Bookshelf), 2025); Anatomy, Head and Neck, Larynx Recurrent Laryngeal Nerve (StatPearls (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.