Physiological Correlates of the Spectral Aggregate of the High-Passed Fundamental Frequency in Adductor Laryngeal Dystonia.

OBJECTIVE

The spectral aggregate of the high-passed fundamental frequency (SAHfo) is an automated acoustic measure associated with the primary acoustic discontinuities present in the speech of individuals with adductor laryngeal dystonia (AdLD). Acoustic discontinuities (e.g., phonation breaks, frequency shifts, creak) are also associated with supraglottic compression and visual laryngeal obstruction postures that occur during laryngeal spasms (i.e., phasic or tonic laryngeal dystonic activity). The purpose of this study was to determine whether SAHfo is similarly reflective of these physiological manifestations of AdLD.

METHOD: Thirty-two speakers with AdLD read voiced and voiceless phoneme-loaded sentences while undergoing transnasal laryngoscopy. Simultaneous microphone and high-speed videoendoscopy signals were recorded. SAHfo was automatically calculated from the acoustic signal, and laryngeal postures (visual laryngeal obstructions, anterior-posterior and mediolateral supraglottic compression) were manually labeled. A generalized linear mixed-effects analysis assessed the effects of sentence type (voiced, voiceless), obstruction events (obstructed view of vocal folds, visible vocal folds), mediolateral compression, anterior-posterior compression, and the interaction of Mediolateral × Anterior-Posterior compression on SAHfo.

RESULTS

Sentence type, obstruction events, and mediolateral compression were significantly related to SAHfo. Anterior-posterior compression did not have a significant effect, but there was a significant interaction between mediolateral and anterior-posterior compression. SAHfo was significantly lower when both mediolateral and anterior-posterior compression were mild and significantly higher when mediolateral compression was severe, regardless of presence or severity of anterior-posterior compression.

CONCLUSION

Findings suggest that SAHfo is related to the laryngeal postures associated with AdLD-specific acoustic discontinuities, providing preliminary physiological support of the use of SAHfo in speakers with AdLD.