Vocal Fold Vibration Associated With Inspiratory Phonation-An Acoustic and Electroglottographic Study

Different from normal or expiratory phonation (EP), inspiratory phonation (IP) involves the use of an ingressive airflow and it is frequently used in clinical voice assessment and treatment. The present study examined the voice quality and glottal vibratory characteristics associated with IP through acoustic (AC) and electroglottographic (EGG) analyses.

The AC and EGG signals of the vowel /i/ produced by 43 young, vocally healthy adults using IP and EP were simultaneously recorded and analyzed using Praat. Contact-related measures derived from EGG signals included contact quotient (CQ), CQ perturbation (CQP), contact index (CI), relative contact rise time (RT), amplitude of contact phase (Amp_con), slope of contacting phase (Slope_con), and slope of decontacting phase (Slope_decon). Additionally, fundamental frequency (F0), percent jitter (%Jitter), percent shimmer (%Shimmer), and harmonic-to-noise ratio (HNR) were extracted from both EGG and AC signals.

CQP, CI, and RT increased and Amp_con and Slope_con decreased when using IP, but no significant differences in CQ and Slope_decon between EP and IP. F0_EGG, %Jitter_EGG, and %Shimmer_EGG increased during IP, while HNR_EGG decreased. Similarly, F0_AC, %Jitter_AC, and %Shimmer_AC increased during IP, with no significant difference between IP and EP for HNR_AC.

Marked differences in glottal vibration were identified for IP when compared with EP, with the latter having been studied more extensively. Given the clinical value of IP, further characterization is warranted to elucidate the specific role this maneuver may play in the differential diagnosis and treatment of laryngeal pathology.