Medical Speech Pathology

Curiosity, Dialogue, and Knowledge


Illustration by Karen Nichols


The human voice is an amazing instrument.  Sound waves are generated by air passing through the vibrating membranes of your vocal cords, which then reverberate through your pharynx, nasal passages, and mouth.  Depending on the size of the vocal cords, the frequency of the sound is changed.  Small vocal cords vibrate quickly (the fundamental frequency for an average female is 200 cycles per second or hertz), and larger vocal cords vibrate more slowly (for males the number is around 125 Hz). A cycle, in this case is the same as the wavelength.

For more detailed information on anatomy and voice see the fantastic site, The National Center for Voice and Speech.

Voice problems can come about from a variety of reasons: genetic problems, vocal trauma, vocal abuse/misuse, neurological diseases, and cancer.  Of course, if you are experiencing voice problems and the cause isn’t clear, then you should see your doctor.

ASHA’s position statement on dysphonia (voice problems), cites a lot of sound articles to back up the idea that we as speech therapists are uniquely trained to help treat vocal problems once a doctor diagnoses them.  Our role is to help patients reduce behavioral abuse, increase vocal hygiene, help to strengthen the laryngeal musculature, and work alongside other medical interventions before or after they occur. A good example of this would be working with a patient that has unilateral vocal cord paralysis or paresis.  In this instance, we may very well help out initially with the patient as they recover from a stroke (a common cause of this diagnosis), inform them of options if they are concerned about their voice, and then follow up with them after they have seen an ENT (Ear Nose and Throat Doctor).  There are different ways to treat this problem, which include: vocal cord medialization thyroplasty,  cord injections (teflon, collagen, autologous fat, and synthetic injectables), and reinnervation surgery.  For in-depth information on these treatment options see Vocal Cord Paralysis and Vocal Cord Medialization.

An important thing to remember about our role in treatment and evaluation of voice problems is the necessarily collaborative relationship that we must have with the treating physician.  At a minimum, we must have a clear diagnosis for the problem.  All of us can discern vocal dysfunction, and most can tell what quality, loudness, pitch, and intonation problems exist, but without a proper diagnosis treatment is at best a shot in the dark.  At worst, treating a problem without having the correct diagnosis could lead to negative medical outcomes for the patient.

Further information on specific voice therapy techniques and particular diagnoses will be forthcoming!

Enjoy a video here showing what the vocal cords look like when they are doing what they do best.

Youtube of Vocal Cords in Motion

7 comments on “Voice

  1. chemistryinmedicine
    May 22, 2012

    Really interesting information about how the voice works- thanks for teaching me something new about the voice and its problems

    • Admin
      May 22, 2012

      Thanks for dropping by and taking a look around. I’ll keep updating the site as often as possible. Good work on your own site by the way. It’s informative and very approachable.

  2. logopedaenlared
    September 17, 2014

    Im like your blog and now I’m following you!!! Im really interested in all these ideas!!

    • Admin
      September 17, 2014

      Thanks! I’ll try and keep more content coming. Feel free to contribute too, if you get the itch.

      • logopedaenlared
        September 17, 2014

        Im from Spain and im studying speech therapist. This is my last year and im writting things about this matter too. I hope that you understand me because i have problems when i write in english. I prefer speak than write.

        Thanks for your time!!

  3. jenniferscott
    January 14, 2018

    Hello! I found you blog while looking for information for an undergraduate lecture. There is a lot of wonderful information here, but I would caution you that amplitude is mislabeled on the above diagram. Amplitude is measured from the zero degree axisto the peak. What you have marked is a peak to peak measurement, which is actually 2 X amplitude.

    • Admin
      January 15, 2018

      Thanks for the correction.

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