“Please, Mind the Gap”
Getting around the city of London on the Tube also known as the London Underground, each time the train stops and the doors slide open, both in and outside the train an announcer comes on with the phrase, “Please, mind the gap.” Signs on the walls remind passengers to “Mind the gap.” While riding the Tube, over and over one hears, “Mind the gap.” The gap between the train and the platform can be the source of all sorts of serious problems, but is otherwise ignored by the millions riding the rails around London.
A laryngologist would do well to ride the tube until; “Mind the gap” becomes second nature. The gap between the vocal cords deserves your primary attention, and it is easily ignored while looking at all the other structures around, although the gap is the most significant location to find the source of hoarseness. So, “Mind the gap!”
Remember, under presumed ideal conditions the posterior portion of the vocal cords move completely together during voice production and the vocal cords lie parallel to each other. Air is blown between them and the vocal cords rapidly open and then completely close, letting out regular pulses of air. Regular pulses lead to harmonic movement of air and consequently are heard as a pure tone.
In what ways might the vocal cords incompletely close? There are a couple of characteristic types of gaps that occur between the vocal cords:
- Posterior gap
- Anterior gap
- Central gap
- Split gap
- Timing gap
All of these types of gaps leak air and create a husky hoarseness.