1. Helping children produce accurate vowels makes a HUGE differences in their intelligibility. Consider this sentence: "I eat two potatoes." A child who has all of their vowels intact but no consonants would produce it like " I ee ooo ah-A-O." vs. a child who has most of their consonants but reverts to a lax "ah" vowel. "Ah aht tah pahtahtah." With a little bit of context the first child is going to be easier to understand. Vowels are especially important for clients with lower muscle tone or medical diagnoses such as Down Syndrome.
2. While there is agreement that vowels are an important part of intelligibility, there are few treatment materials or continuing education courses which address vowel production. Deborah Hayden's PROMPT therapy does the best job I've found so far in addressing vowel production in speech. To learn more about PROMPT therapy please visit the PROMPT institute website here.
3. This was the second TPT activity that I was able to get my husband, a professional illustrator, to provide some of clip art. He is really talented and it's just fun to work on things together.
Anyhow, My newly revised PENGUIN VOWELS increased from 28 pages to 42 pages of materials. New additions included: Cheat sheets for common spellings of long vowels and hints for productions of long/short vowels and dipthongs.
HERE. I hope you enjoy is as much as I do!