"Use your lips, not your tongue." That was what I'd say when we started with Straw #4 in the beginning of June. I doubt many parents have to give their children specific (and odd) instruction on how to drink with a straw.
Straw #4 is relatively a shorter straw and has a smaller diameter than straw #3. The smaller diameter makes straw #4 a challenge. In the beginning, I used a lip block (as shown in the photo) to control how much straw tip goes into Matthew's mouth.
Without the lip block, verbal prompts or reminders "use your lips, not your tongue" and my fingers positioned 1/4-inch from the drinking tip were necessary to get a similar effect as having the lip block in place. Then I re-read the instructions and learned that I was supposed to cut the straw close enough to the first loop so that the loop served as a lip block. So I cut the straw and did away with the yellow rubber lip block.
After 4 months of using straw #4, I have noticed better and stronger lip closure. Along with this physical progress, I have noticed clearer articulation of single speech sounds. Stringing sounds together is still a work in progress though.
I don't doubt that the straws have been helping Matthew develop a stronger oral foundation for speech but his progress in speech is really a combination of the right amounts of speech therapy, reading sight words, oral stimulation techniques (including use of the TalkTools straw kit), and articulation practice. Other oral stimulation techniques include using a z-vibe and offering food that require a lot of chewing or brings more awareness to the mouth such as pickles, grilled chicken, grilled steak, fresh cut apples, lemon sorbet, and so on.
Since the end of September, he easily and successfully (no leaking) drank 4 ounces of milk or juice with straw #4 in one uninterrupted sitting and with less prompting. He has moved on to straw #5!