Consistency of fundamental frequency and perturbation in repeated phonations of sustained vowels, reading, and connected speech.

The purpose of this study was to determine consistency of the acoustic measurement of fundamental frequency (f0) and f0 perturbation using the Visi-Pitch. Samples of speech including a reading passage, vowels, and spontaneous speech were recorded for 12 normal young adults (6 men and 6 women). The results indicated that test-retest reliability was highest for the reading passage. The measurements of fundamental frequency for reading and spontaneous speech were very similar, but vowel production was, on average, higher in frequency than the other contexts. Test-retest measures of perturbation using the Visi-Pitch did not have a high correlation coefficient. Perturbation measures must be interpreted cautiously because of the influence of frequency.