Flow Glottogram Characteristics and Perceived Degree of Phonatory Pressedness.

OBJECTIVES

Phonatory pressedness is a clinically relevant aspect of voice, which generally is analyzed by auditory perception. The present investigation aimed at identifying voice source and formant characteristics related to experts' ratings of phonatory pressedness.

STUDY

DESIGN

Experimental study of the relations between visual analog scale ratings of phonatory pressedness and voice source parameters in healthy voices.

METHODS

Audio, electroglottogram, and subglottal pressure, estimated from oral pressure during /p/ occlusion, were recorded from five female and six male subjects, each of whom deliberately varied phonation type between neutral, flow, and pressed in the syllable /pae/, produced at three loudness levels and three pitches. Speech-language pathologists rated, along a visual analog scale, the degree of perceived phonatory pressedness in these samples.

RESULTS

The samples were analyzed by means of inverse filtering with regard to closed quotient, dominance of the voice source fundamental, normalized amplitude quotient, peak-to-peak flow amplitude, as well as formant frequencies and the alpha ratio of spectrum energy above and below 1000 Hz. The results were compared with the rating data, which showed that the ratings were closely related to voice source parameters.

CONCLUSIONS

Approximately, 70% of the variance of the ratings could be explained by the voice source parameters. A multiple linear regression analysis suggested that perceived phonatory pressedness is related most closely to subglottal pressure, closed quotient, and the two lowest formants.