Inverse-filtered air flow and EGG measures for sustained vowels and syllables.

The purpose of this investigation was to compare the effects of two speaking tasks on laryngeal measures obtained from inverse-filtered air flow and electroglottograph (EGG) waveforms. Flow amplitude, air flow duty cycle, EGG duty cycle, and fundamental frequency were measured for normal young and aged adults during vowel prolongation and syllable repetition. There were significant between-task differences for flow amplitude and fundamental frequency. Variability appeared no greater for syllable repetition than vowel prolongations. Syllable repetition was slightly better than vowel prolongation for differentiating the vocal behaviors of aged and young speakers. Between-task relationships were strong for fundamental frequency and more moderate for the other laryngeal measures. It was concluded that syllable repetition would be preferable to vowel prolongation for measurement of aerodynamic and EGG parameters and that findings could be generalized across speaking tasks for fundamental frequency but not air flow and duty cycle measures.