Effortful trial and error with groping

Groping is when the mouth searches for the position needed to create a sound. When this trial and error process occurs, sounds may be held out longer, repeated or silently voiced. In some cases, someone with AOS may be able to produce certain sounds on their own, easily and unconsciously, but when prompted by another to produce the same sound the patient may grope with their lips, using volitional control (conscious awareness of the attempted speech movements), while struggling to produce the sound.

-Wikipedia (https://en.wikipedia.org/wiki/Apraxia_of_speech)