Esophageal Airflow

The normal function of the esophagus is conveying swallowed food to the stomach. However the esophagus can also play a role in speech production. There are two main ways this can be done; one involves esophageal air, the other involves pulmonic air.

Using esophageal air

This technique consists of swallowing air into your esophagus, then using your esophageal muscles to make it flow back up again. Most of us do this when we actively generate a belch.
However for people who have had their larynx surgically removed, this technique can be used as an alternative way of speaking. This is an extraordinary skill, and involves considerable learning;

  • swallowing air by a movement called a ‘tongue press’
  • a slow controlled rate of ‘exhaled’ airflow
  • rapidly contracting a hand of muscle at the top of the esophagus to approximate the phonation action of the vocal folds.

Play the animation of esophageal technique. Note that the larynx is missing, and that the trachea in this animation opens through a hole (stoma) in the throat. The trachea is used for breathing, but plays no role in speaking.
Mastering this technique is very hard to learn, and requires intensive therapy. Large numbers of laryngectomisecl patients never develop good functional speech this way. Scroll down to see some more popular alternatives.

Using pulmonary air

This technique involves having a one-way silicon valve surgically inserted between the trachea and esophagus. Placing a thumb over the tracheal hole (stoma) diverts air flow from the trachea through to the esophagus, where a band of muscle at the top of the esophagus can be used to approximate the phonation action of the vocal folds.
Play the animation to see the details of this technique.
This mechanism has the major advantage of using of normal pulmonary airflow, allowing the normal pattern of short inhalation and easily controlled slow exhalation. It also avoids the bloated stomach feeling that esopohageal airflow can cause. For these reasons, this technique is now much more popular than the esophageal technique.
Further down you can play a video of Pat demonstrating speech using the prosthesis technique. You’ll notice that when you first hear Pat speak, you might find it difficult to understand, but on replaying this clip, you’ll find that your hearing quickly attunes to the particular characteristics of her speech.
Also below you can learn about how to insert and care for a tracheoesophageal valve, and play a video that shows Pat changing hers.

Speaking with a voice prosthesis

The top video shows Pat speaking. Play it now.

Inserting the voice prosthesis

The tracheoesophageal valve needs considerable maintenance;

  • it must be regularly removed
  • a catheter (or dilator) inserted to keep the hole open
  • the valve cleaned, either with a pipe cleaner, or svringed with water, and then sterilised
  • then the catheter removed
  • and the cleaned valve reinserted

A tracheo-esophageal valve lasts only a few months, and is quite expensive.
The lower video shows Pat changing her valve. Play it now.
Technologically advanced alternatives to the prosthesis are increasingly becoming available;

  • The tracheostoma valve can be glued around the stoma allowing ‘hands-free’ use. With it, it is not necessary to manually block the stoma with the thumb in order to direct airflow through the tracheo-esophageal valve.
  • It is now also possible to have an indwelling low pressure prosthesis surgically implanted. This should last 3-6 months without needing to be removed for regular maintenance.

Using an artificial larynx

Finally, we should consider another technique which allows a person who has had their larynx removed to speak, but which requires no airflow at all. The artificial larynx is a small device which generates a regular sound wave. It is hand-held against the upper side of the throat, and the sound pulses through the jaw bone and soft tissue, and resonates inside the oral cavity. Just like sound waves generated by the vocal folds, these artificially induced resonating sound waves can be shaped into distinct vowels and consonants by normal articulation.
Play the video of John speaking with a SerVox artificial larynx. This model provides a choice between two pitch settings; a typical male and female pitch. There is also a volume control.
This technique has the advantage of being fairly easy to learn, and requires no surgery bevond the laryngectomy itself. The main disadvantages are the distinctively artifical voice quality, and the inabilitv to vary pitch and volume in ways that sound natural.