Fundamental frequency histograms measured by electroglottography during speech: a pilot study for standardization.

This study was designed to develop a database for the electroglottographic measurement of fundamental frequency (Fo) in normal subjects in running speech, for reference in the diagnosis and follow-up of dysphonic patients. A prospective pilot study included 20 healthy male volunteers without laryngeal disorder. Electroglottographic recordings of speaking Fo during connected speech (French) were obtained from two texts with different prosodic content. Fo histograms were sensitive to the variation of speaking Fo between both texts. Graphic representation of the range and distribution of the Fo of the speaker were designed as normalized Fo histograms with plot lines at 5th and 95th percentiles. Less than 5% variability of Fo histograms was recorded when recording more than 15 subjects. This pilot study designed a graphic display of standardized electroglottographic Fo measurements during the physiological condition of connected speech. As the degree of Fo variability depends on the phonetic contents of the text and on the language spoken, a separate histogram for normal subjects needs to be developed in each country or at least for each voice laboratory, with a standard, previously chosen text.