Larynx
The larynx, also known as the voice box, is an organ of the anterior neck involved with breathing, phonation, and protection of the trachea. The vocal cords are housed within the larynx. The larynx connects the inferior part of the pharynx with the trachea.
Below are images of a normal larynx, offered as a point of comparison for all of the examples of laryngeal diseases and disorders elsewhere on Laryngopedia. One can reasonably call the vocal cords, “laryngeal lips.” Thinking of a trumpeter’s lips as an analogy, he or she separates them to take a breath, and then pinches them together to “buzz” into the mouth piece of the trumpet. Similarly, the laryngeal lips separate for breathing, though in a V-shaped opening, and then press together in a line to “buzz” into the vocal tract. One could almost play the trumpet using the laryngeal lips!
Vocal cords (1 of 7)
The line of sight is from directly above these open (for breathing) vocal cords, and downward in the line of the trachea. The difference in vocal cord width is not real, but a function of the angle of viewing. This is the position of the vocal cords while breathing.
Vocal cords during voice (2 of 7)
Here the vocal cords are producing sound at G2 (98Hz). Under standard light, vibration is so rapid that it is perceived as a blurring of the margins.
Vibration in rubber bands (3 of 7)
Twang a thick rubber band and you will see the same kind of blurring phenomenon because vibration is so rapid.
Phonation under strobe light (4 of 7)
During voicing (phonation), under strobe light, to provide apparent slow motion view of vibration. This is the closed phase of vibration at A2 (110 Hz, or 110 vibration cycles per second).
Open phase of vibration (5 of 7)
The open phase of vibration, also at A2. For emphasis: This cycling between open and closed phases of vibration occurs 110 times per second at A2!
Clodes phase of vibration (6 of 7)
Now at A4 (440 Hz), this is one of 440 closed phases of vibration per second.
Open phase (7 of 7)
One of 440 open phases of vibration that occurs per second, again as seen under strobe light.
More Photos:
Larynx: breathing position (1 of 2)
Normal larynx with vocal cords in abducted, breathing position. This is a view from from above, looking on line with the trachea beyond the vocal cords.
Larynx: phonatory position (2 of 2)
Normal larynx with cords in adducted, phonatory (voicing) position. Continuous light. Notice the straight match of the cords, and the narrow, physiologic gap between the cords at the prephonatory instant, just before vibratory blurring.
Nicotine Staining of a Damaged Larynx
Heavy smoker (1 of 2)
Severe diffuse thickening, dryness, and irregularity of all areas of the larynx in a heavy smoker.
Closer view (2 of 2)
In this closer view, the golden brown color on the vocal cords is “tar and nicotine” staining. In a wetter, smoother larynx, the mucus blanket tends to “flow” to keep the staining from appearing. This larynx provides a visual representation of what is in cigarette smoke.
Pitch Effects on Vocal Cord Length and Vibratory Amplitude
Abducted breathing position (1 of 10)
Abducted (separated) vocal cords, during breathing.
Phonatory blurring (2 of 10)
Making voice under standard light at G2 (~98 Hz), showing blurring of the margins ßà due to 98 vibrations per second! Pluck a rubber band at low tension for a visual analogy.
Phonation (3 of 10)
Voicing, but now at a pitch nearly 2 octaves higher, E4 (~330 Hz). Vocal cords are stretched lengthwise (longer) and vibratory amplitude much less, and this explains the narrower blur. See also photos 7 and 8. Stretch and then pluck the same rubber band for a visual analogy.
Open phase, A2 (4 of 10)
Under strobe light, the open phase of vibration, using a breathy, under-energized production to increase the amplitude (distance traveled laterally) of vibration.
Closed phase, A2 (5 of 10)
Closed phase of vibration at A2 (~110 Hz).
Open phase, firm voice (6 of 10)
Open phase of vibration using a firm voice production and this reduces the amplitude of vibration as compared with Photo 4, even though the pitch is the same as in that photo.
Closed phase, E4 (7 of 10)
Closed phase of vibration at E4 (~330 Hz).
Open phase, E4 (8 of 10)
Open phase also at E4, showing the smaller amplitude of vibration and explaining why the grey margin blur seen in photo 3 is “narrow” as compared with when vibratory amplitude is greater.
Closed phase, A4 (9 of 10)
Closed phase of vibration at A4 (~440 Hz). Vocal cords are lengthened to create high pitch (compare especially with photo 5).
Open phase, A4 (10 of 10)
Open phase vibration also at A4. Amplitude at this high pitch is less than for E4 (photo 8) and certainly than at A2 (photo 6). Note that amplitude of vibration is altered by loudness and not only pitch.
The Asthenic But Normal Larynx
Asthenic larynx (1 of 6)
This quiet, soft-spoken teenager was being examined for a reason other than her voice. On an incidental basis, hers is a good example of the asthenic larynx. Detailed findings described in Photo 2.
Slender vocal cords (2 of 6)
Closer view under narrow band light. Note how slender her vocal cords are. Ventricles are capacious. There is no “conus” bulk below the vocal cord margins.
Prephonatory instant (3 of 6)
At the prephonatory instant for G5 (784 Hz), standard light. Note the significant space between the cords, but not due to MTD, in that the posterior cords are fully adducted.
Phonatory view (4 of 6)
Also at G5, vibration blurs the margins.
Strobe light (5 of 6)
Under strobe light at F5 (698 Hz). Posterior vocal cords remain together.
Closed phase (6 of 6)
Still at F5, but closed phase of vibration is not fully closed.
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