2. There are many possible sources of perturbation and fluctuation in the voice. Some of them are neurologic, biomechanical, aerodynamic and/or acoustic.
True
False

3. A trillo is rapid repetition (at 9 to 12 Hz) of the same note with repeated voice onset and offset.
True
False

4. Shimmer is long-term variability in amplitude.
True
False

5. Vibrato involves both frequency and amplitude modulation.
True
False

6. Normal vibrato rate is from 2-4 Hz.
True
False

7. The difference between trill and vibrato is that the average pitch is raised in vibrato, but not in trill.
True
False

8. Vocal trillo can be produced at a frequency greater than vocal vibrato because the adductory muscles are faster than the cricothyroid and thyroarytenoid muscles.
True
False