Relationship between Articulator Position and Resonance

Question

What will be an ideal response?

Answer 1

I find it useful to discuss the relationship between articulatory position and resonance. Although students have knowledge of resonance and the relationships, experience playing with resonance seems to be useful.

1. First, help students grasp the source-filter theory. Source is, of course, the vocal folds (for vowels), but what about the alternate sources for other phonemes? Try whispering vowels, or even rapping your skull with your knuckles to cause excitation of the oral cavity as you move through different vowels. Slapping your cheeks can also be a good excitatory mode, as can an electrolarynx.

2. Now discuss the relationship between cavity size and articulation. In basic terms, help students understand that small is high frequency, and large is low frequency. To do this, have them describe the difference between “sh” and /s/ in terms of size of cavity ahead of the constriction. Then produce /s/ and slide your tongue back to “sh.” Students should be able to hear the resonant frequency shift down as you do this.

3. Soda bottles are a great means of demonstrating cavity resonance. If you have forgotten to bring any in, you can call on the people with water bottles; bring them to the front and line them up in random order of the size of cavity of the bottle (i.e., the cavity that does not have liquid in it). Have students blow across the bottle tops in sequence to demonstrate the effect of volume on resonance (more volume = lower frequency).
You can do the same thing with your own bottles, or a single bottle. Using a single bottle full of water, blow across the top. Then empty some water out and blow again. Repeat this sequence to show the volume relationship. This is a good time, also, to ask students why blowing across the bottle top creates these wonderful tones.
You can cut one of these bottles down in advance so that you have only the bottle neck. If you blow across it, you get only the broad-spectrum noise generated by the turbulence across the lip. This is analogous to the noise produced at the point of constriction in the vocal tract by articulation, and is a great source of demonstration.