The Larynx or the voice box is an amazing organ that allows us to make sounds. Imagine what would happen if the larynx is taken away from us! The human world will become mute. In this article on larynx facts we are going to take a good look at the organ. In the process, we will learn why and just how much important it is to us.
Apart from that, we will also learn some random larynx facts (or you can call vocal cord facts) that will leave you surprised! Are you ready? Yes you are as always! Let’s begin.
Larynx Facts or Vocal Cords Facts: General Facts | 1-5
1. Larynx is generally called the voice box or the vocal cords. It is the organ primarily responsible for the production of voice.
2. It sits at the top of the neck of tetrapods (animals which have four limbs – aves, amphibians, reptiles, mammals etc.)
3. The word larynx originates from the ancient Greek word “λάρυγξ” or larynx.
4. A Greek physician, Galen was the first one to describe larynx. He described it as “first and supremely most important instrument of the voice.”
5. It is situated below the split of the tract of pharynx into trachea and esophagus.
Larynx Facts or Vocal Cords Facts: Structure of Larynx | 6-10
6. It is triangular in shape. It is mostly made up of cartilages which are attached to each other and are connected to the surrounding structures by either muscles or elastic or fibrous tissue components.
7. It suspends from the hyoid bone. Epiglottis is the inlet of the larynx. It continues to circular outlet of cricoid cartilage.
8. It remains continuous with the lumen or cavity of trachea inferiorly (or below), and superiorly (above) it opens into laryngeal pharynx.
9. It is covered with infrahyoid muscles anteriorly (part of larynx which is close to the head) and thyroid gland covers the larynx from sides (laterally). Posterior to the larynx is the esophagus.
10. The mucous membrane that lines the larynx produces 2 pairs of lateral folds which protrude inwards into the lumen of the larynx.
Larynx Facts or Vocal Cords Facts: Structure of Larynx | 11-15
11. Upper folds are known as vestibular folds. They are also called the false vocal cords because they don’t play any role in producing sounds. They however help in resonance. They don’t have any muscles.
12. The lower folds are called the vocal cords or true vocal folds as they are the ones that produce sound. They have skeletal muscles.
13. These folds are longer and have more mass in men (this change happens during puberty. Pre-puberty the folds are same for both the genders) when compared to the vocal folds present in women.
14. A small slit like space which is present between right and left folds is the narrowest part of the larynx. It is called the Rima glottidis.
15. The lumen of the larynx is divided into three parts which are as follows:
Supraglottis: The cavity of larynx from epiglottis’ surface to the vestibular folds is called supraglottis.
Glottis: The vocal folds and Rima glottidis are considered as the glottis.
Subglottis: The lumen of larynx from the lower end of the glottis to the lower border of the cricoid cartilage is the subglottis.
Larynx Facts or Vocal Cords Facts: Structure of Larynx | 16-20
16. The cavity of the larynx above the false vocal cords is known as vestibule.
17. The cavity of the larynx present between these two pairs of folds is called the ventricle of the larynx or laryngeal ventricle.
18. Space below the glottis is called the infraglottic cavity.
19. Larynx has a lining of ciliated mucous membrane on the outer surface. The inner surface of voice box is lined with pseudostratified ciliated columnar epithelium.
20. The only exception to this lining is the epithelium of true vocal cords. True vocal cords are lined with stratified squamous epithelium.
Larynx Facts or Vocal Cords Facts: Cartilages of Larynx | 21-23
21. There are in total six cartilages of larynx. Of these six, three are paired cartilages and the rest three are unpaired cartilages.
22. The unpaired cartilages are thyroid cartilage, cricoid cartilage, and epiglottis.
Thyroid cartilage: Adam’s apple is formed by thyroid cartilage. A ligament called thyrohyoid membrane connects hyoid bone with the thyroid cartilage. It is larger in males compared to females.
Epiglottis: It is a flap-like spoon shaped elastic cartilage which covers the glottis or the opening of the esophagus. We wrote an article about epiglottis, its structure and how it works which you can find here.
Cricoid cartilage: This cartilage is actually a ring of cartilage which makes up the inferior wall of the larynx. It is glassy and translucent. It is attached to trachea’s anterior side and it is connected to thyroid cartilage via median cricothyroid ligament.
23. The paired cartilages are corniculate cartilages, cuneiform cartilages, and arytenoid cartilages.
Arytenoid cartilages: Of the three paired cartilages, this pair is important because they affect the tension and position of the vocal folds. They are triangular in shape and are glassy and translucent. Arytenoid cartilages stay attached at the posterosuperior border of the cricoid cartilage.
Corniculate cartilages: These cartilages are attached at the top of the Arytenoid cartilages. They are horn shaped.
Cuneiform cartilages: These cartilages are attached to the anterior side of the corniculate cartilages. They are club shaped.
Larynx Facts or Vocal Cords Facts: Muscles of Larynx | 24-30
24. There are many muscles which help larynx to perform its functions efficiently. There are two types of muscles – intrinsic and extrinsic muscles.
25. Intrinsic muscles are yet again divided into phonatory and respiratory muscles.
26. Respiratory muscles move the vocal cords away to help breathing. Phonatory muscles move the vocal cords together to produce sound.
27. Respiratory muscles are posterior cricoarytenoid muscles. This is the only muscle which is capable of separating the vocal folds and helps in breathing.
28. Phonatory muscles are lateral cricoarytenoid muscles, arytenoid muscles, thyroarytenoid muscles and cricothyroid muscles.
29. Extrinsic muscles help in supporting the larynx and in keeping the larynx in its position in mid-cervical region.
30. Extrinsic muscles are:
Inferior constrictor muscles
Larynx Facts or Vocal Cords Facts: Functions of Larynx | 31-35
31. It is a known fact (at least by now) that the larynx is the organ which produces sound and it is its primary function.
32. It is where the volume and pitch are manipulated. Though larynx is the primary organ to produce sound, organs like tongue, pharynx, mouth, lips etc. also play a role in altering the sound.
33. It is because of the organs of the vocal tract (larynx, pharynx, nasal cavity, and oral cavity) that a person can make voice modulations and can make changes in tone, pitch, etc.
34. Larynx prevents any particles entering into lungs by coughing or other similar reflexes.
35. By coughing, the irritant is thrown out from the throat. Throat cleaning is also used to protect the respiratory tract.
Larynx Facts or Vocal Cords Facts: Functions of Larynx | 36-40
36. Both coughing and throat cleaning contract the laryngeal muscles and vocal folds. Both are voluntary and put vocal folds under considerable strain.
37. Separation of vocal folds is necessary for physical exertion. When forced respiration takes place, the vocal folds separate by about 16 mm whereas the vocal folds separate by about 8 mm during normal respiration.
38. Abdominal fixation while lifting heavy weights is another important function of larynx. Vocal folds contract and move closer which allows the lungs to hold air and tighten the thorax.
39. When we lift any heavy object, the force of lifting goes to the legs during abdominal fixation and it gets easy to lift the objects.
40. Did you know grunting is the sound produced when some air escapes out from vocal folds?
Larynx Facts or Vocal Cords Facts: Medical Issues Related to Larynx | 41-48
41. Just like pharynx, esophagus, trachea, or salivary glands, the larynx is also easily taken for granted. However, there are many medical issues which can hamper the functioning of larynx.
42. Some of the common symptoms are hoarseness, pain in throat and ears, loss of voice, breathing difficulties.
43. Acute laryngitis is the inflammation and swelling of larynx. It may be caused by cold, or excessive shouting and is not really serious.
44. Chronic laryngitis is same as acute laryngitis but it is more serious than acute laryngitis. It may be caused by smoking, continuous exposure to polluted air for long, dust etc.
45. Presbylarynx is an age-related issue of larynx where the soft tissues get shrunk as the adults age.
46. Other issues which effects the functioning of larynx are polyps (due to smoking), nodules (due to vocal misuse), laryngeal paralysis (vocal folds don’t open up completely which obstructs in respiration), laryngeal perichondritis (inflammation of perichondrium of cartilages of larynx) etc.
47. There are two types of laryngeal cancers – squamous cell carcinoma and verrucous carcinoma.
48. These two cancers are caused due to continuous and repeated exposure to smoking and alcohol.
Larynx Facts or Vocal Cords Facts: General Facts on Vocal Cords and Voice | 49-56
49. Transplant of larynx is extremely rare. The first ever successful larynx transplant took place in the year 1998 in Cleveland Clinic.
50. The second transplant took place in October 2010 in Sacramento’s University of California Davis Medical Center.
51. Larynx in children is located higher when compared to the position of the larynx in adults. As the child grows, the larynx descends.
52. As per the director of National Center for Voice and Speech (at the University of Utah), Ingo Titze, it is almost impossible to create an instrument which can elongate and vibrate like the human vocal cords.
53. Though they are extremely important and some people’s voice is just music to our ears, the laparoscopic action of these mucus laden vocal cords is certainly not as amazing as the voices it produces.
54. Voice has three parts – power source (breath), vibratory source (vocal cords) and the amplification (vocal tract, throat, nose, mouth etc.)
55. Your vocal cords just produce sound. The vocal tract, lungs, and diaphragm, etc. are the ones to be trained to sing a song properly. So, if you have a good voice but missing out somewhere, then all we can say is practice!
56. A study also proved that there is no such thing called good singers or bad singers! Another study proves that singing is an ability which works on “use it or else lose it” policy.
Larynx Facts or Vocal Cords Facts: General Facts on Vocal Cords and Voice | 57-64
57. Singers mostly depend on their lungs because the more lungs can store oxygen, the longer they can hold their breath and sing comfortably.
58. If you have any breathing issues then sing a song every day. There are high chances that your breathing issues will decrease to an extent (as per the study on COPD or Chronic Obstructive Pulmonary Disease).
59. Missouri’s Tim Storms earned a place in Guinness World Record for having the widest vocal range (of humans) of 10 octaves.
60. He has the world’s deepest voice where he can produce sounds of as low as 0.189 Hz (normal hearing capacity is 20 Hz to 20,000 Hz and we speak at frequency of 65 to 260 Hz).
61. Victor Negus, a British comparative anatomist, studied the structure and evolution of larynx in detail in 1920’s and published The Mechanism of the Larynx in the year 1929.
62. The muscles that we use for swallowing are the ones which work when we talk.
63. Contrary to our belief or at least expectations, whispering strains our vocal cords more than talking softly.
64. There is something called Maximum Phonation Time (MPT). MPT is an average time where an individual can produce a sound in one breath at uniform and comfortable loudness and pitch.
Larynx Facts or Vocal Cords Facts: General Facts on Vocal Cords and Voice | 65-72
65. For an average human, MPT of 15 seconds is normal.
66. Here is a surprise for you. Though we ladies are infamous for talking a lot, men (20 seconds) take the spot of having longer MPT than women (15 seconds)! Children have 10 seconds of MPT.
67. A shorter MPT shows that there is inefficiency of respiratory or phonatory system
68. Shape of a person’s vocal tract is partly learned and partly genetic. It is because of this, we can improve the sounds that we produce.
69. If you think that the shape of vocal tract is the only thing which affects your voice then, oh boy, you are so very wrong. In fact, your voice depends on the size and shape of your body as well. Hence each and everyone’s voice is unique.
70. As the shape of the neck, chest, position of your tongue and tightness of muscles in unrelated areas gets altered, pitch, tone, timbre etc. of your voice also changes.
71. For you to speak a phrase, your body uses 100 different type of muscles (tongue, lips, jaw, chest, neck etc.)
72. According to a study conducted in 2010, mother’s voice decreases the stress experienced by an infant and releases oxytocin which is a hormone linked with love and bonding.
Larynx Facts or Vocal Cords Facts: General Facts on Vocal Cords and Voice | 73-78
73. Did you know that listeners (who listen to voice samples) can deduce the speaker’s socioeconomic status, age, height, personality traits, mental and emotional state, weight etc.
74. Listeners have the same amount of accuracy achieved in deducing such characteristics while examining the photographs.
75. When the fetus is of 25 weeks, it has the ability of recognizing and responding to its mother’s voice. This is the reason why when the baby is born, it shows preference to its mother than other women’s voices.
76. Do you know why people hate their own voices? It is because the energy bounces back in our mouth, throat, brain and inner parts of our ears. Other people can’t sense these vibrations. So, they perceive our voices differently.
77. Men and women lower their pitch when they are talking to an attractive opposite sex person.
78. There is something called Lombard effect. It is nothing but a person’s involuntary change in pitch, voice, rate of syllables when in loud environment.
Larynx Facts or Vocal Cords Facts: General Facts on Vocal Cords and Voice | 79-85
79. When someone talks to you with your headphones on, then you tend to “shout” while replying – a simple everyday example of Lombard effect.
80. According to a study conducted at University of Glasgow, people can judge how trustworthy or dominant you are just by your voice!
81. A study concluded that people who have lower pitches are considered to have more competence, physical power, and integrity.
82. Humans in general prefer human voice over robotic voices.
83. Ancient Sanskrit poets thought that chewing mango buds would sweeten a person’s voice.
84. Richard Fink IV of USA set the longest sustained voice note at 1 minute 43 seconds in 2009.
85. English is spoken at around 6 syllables per second.
Sources: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Featured image: Olek Remesz | Public Domain