A quick analysis will show that you go from one mouth shape that is quite open (Ah in hafta) to a pretty closed one (the F in hafta) and then back open again (for the end of hafta). The result is the mouth popping from open to closed back to open in just three frames.

Oftentimes, beginners will make a phoneme that is an exact copy of one’s face saying that single letter. So, to make “E” phonemes, you would say “E” by itself. To model “K” phonemes, you can base it off your own face in a mirror saying “kuh.” At first this seems logical. The problem is that when you say the “t” sound by itself (“tuh”), your face doesn’t look at all like it would if you said “skate.” And that “t” in “skate” gives a face shape that is completely different from the “t” sound shapes in “pet store.” And THAT “t” is very different from the “t” shape you make when you say “goatee.” Figure 11 shows variations on the “t” shape.

[Figure 11] Working from left to right: the default “t” shape; the “t” shape in the word skate; the “t” shape in get; and the “t” shape in goat.

As such, it’s imperative to remember that mouth shapes for sounds must be animated in context. The preceding sound shape affects the current sound shape. Likewise, the following sound shape is anticipated in the current sound shape.

So, the shapes shown must all be in context with the shape/ sound that precedes it and follows it. If you get stuck on the idea of making all the “t” sounds in a sound-track the same shape, regardless of the prior or following sound/ shape context in the dialogue, then you’re setting yourself up for a popping mouth when you go to view your animation. Animating speech is not animating letters; it’s animating the flow of shapes that are needed to make the sounds.

If you can get the major impressions across in your animation, you can let the little stuff slide. Just like the impressionist would hint at a cluster of leaves with a single daub of his brush, you too should let words and sound shapes slur into the next word or sound shape. Mix the target facial weights together to show a flow. Get away from showing leaves and start showing contrast and form. Talking is more of a flowing thought than an alliterative function of letters.

Looking again at the example phrase, “you hafta get,” a more impressionistic interpretation would be to emphasize the following major accents:

Ooo

aaFF

Eh

Go ahead and say that out loud. “Ooo” as in “scoop,” “aaFF” as in “after,” and “Eh” as in “pet.”
Ooo- aaFF- Eh.

It sounds a lot like “you hafta get,” doesn’t it?

Now go one further. Grab a handheld mirror and say “you hafta get.” Watch how your mouth looks as you say it again. Now, say “ooo- aaFF- eh” a few times. See how very close the two are in how they look? Here is another example of this same principle: Say to your mirror, “I love you.” Then say to it, “elephant shoes.” The two look similar, don’t they? Here’s a breakdown of a few specific choices.

You’ll want to start by letting the “yuh” of you flow into the more open “aa” at the beginning of “hafta.” Skip the specific “ooo” at the end of “you,” because it is not very strong. It’s there, but it gets said while the mouth is transitioning into the beginning of “hafta.” Basically, it slurs into the next word. The “h” of “hafta” is buried in the back of the throat, so the lips don’t really need to show it.

Picking up from the moderately strong “aa” of “hafta,” hit the “f” for two frames to let it read. It’s the major closed point of the phrase, so that needs to line up and read clearly. Then skip the ending “ah” of “hafta” altogether, as well as the “g” of “get.” Both happen under the breath; they’re slurred under the transition from “ff” to the “eh” accent of “get.” Hit that last open pose of “eh.” Then end with an appropriately shaped nearly closed mouth to catch the idea of a “t.” You’ve basically now animated “Ooo-aaFF-Eht.” And you know what? It flows, it feels natural, and it doesn’t pop.