For some vowels, the tongue is more relaxed than for others.
- Both the highest front and back vowels, for example, are Tense. Some real examples are:
- "Lean" (front) & "Luke" (back).
- The next lower vowels are less tense or Lax. Examples are:
- "Lynn" (front) and "Look" (back).
- The mid vowel also, as in "up" is also Lax.
- This is nothing as adults that we can readily feel or see. The muscle tension is orchestrated at a subliminal level during production.
- Lip Rounding: Take a class in speech improvement and you will spend a lot of time practicing to round the lips when producing certain vowels.
- Paradoxically, if you take a class in Ventriloquism, you will spend a lot of time practicing NOT to round the lips for the same sounds! How come?
- Lip rounding is not essential for the production of any of the vowels. But it does have a place in vowel production.