The effect of task type on fundamental frequency in children.

OBJECTIVE The purpose of this study was to examine the influence of task type on the fundamental frequency (F(0)) produced by young children. Fundamental frequency is a parameter which describes the rate of vocal fold vibration. The influence of task type on F(0) values is important for health professionals designing and implementing assessment protocols for children with voice disorders. METHODS Forty-eight healthy children between the ages of 5.0 and 7.11 years were evaluated in this study. Each child completed four tasks used to elicit a voice sample for subsequent analysis of F(0). The tasks included: (a) sustaining the vowel/a/(Vowel), (b) sustaining the vowel embedded in a word at the end of a phrase (Phrase), (c) repeating a sentence (Sentence), and (d) counting from 1 to 10 (Counting). Each child was evaluated by one of two clinicians who had an equal number of years of training and were the same age and gender. RESULTS A repeated measures analysis of variance (ANOVA) was used to examine the influence of task type on F(0) values. The results revealed a significant difference in F(0) between the four elicitation tasks (p=.002). Pair wise comparisons revealed that Counting elicited higher F(0) values compared to Phrase (p=.018) and Sentence tasks (p=.001). There were no significant interaction effects for task by age, gender, or clinician who evaluated the child (p>.05). CONCLUSIONS The results of this study revealed that task type does significantly influence F(0) values in young children. This finding is clinically important as it indicates that the same task should be used to monitor changes in the voice over time in relationship to surgical or behavioral interventions.