A comparison of subglottal and intraoral pressure measurements during phonation.

Intraoral pressure and subglottal pressure, derived from tracheal puncture, were recorded with the electroglottographic signal for one normal speaking male during phonation. The mean subglottal pressure for vowels was also estimated by interpolating the intraoral pressure from surrounding /p/occlusions. The pressure measurements were highly correlated (r = 0.98) and there were small pressure value differences (on average < 2%). The effects of varying speech rate and mode of phonation on the pressure measurements are discussed. A decrease in pressure from the mean subglottal pressure for the open phase and an increase for the closed phase was found during the glottal vibratory cycles.

Glottal area and vibratory patterns studied with simultaneous stroboscopy, flow glottography, and electroglottography.

The purpose of the present study was to examine the relationship between variations in glottal area and vibratory patterns during phonation studied with stroboscopy and glottographic methods. Two normal speaking male and three female subjects were examined by means of simultaneous stroboscopy, flow glottography, and electroglottography. Estimations were made of the glottal area from pressure and flow data using the formula described by van den Berg. Significant correlations were found for the male phonations between estimations and measurements of the minimum glottal area (glottal insufficiency). Estimations of the peak glottal area were also significantly correlated to measured peak glottal area for values below 25 mm2. The estimated minimum area tended to be higher, whereas the estimated peak area values were lower than the corresponding glottal area measurements. This might be explained by variations in glottal and supraglottal geometry for different modes of phonation and by sub- and supraglottal acoustic interaction. Several glottographic parameters for the male phonations were highly correlated with the measurements of glottal insufficiency and also differed significantly between normal, pressed, and breathy hypofunctional modes of phonation. The presence of a hump in the first part of the closed phase for the flow glottogram seems to indicate that a clearly visible mucosal wave is present during vocal fold vibration.

Spectral correlates of glottal voice source waveform characteristics.

The relationships between the waveform and the spectrum of the pulsating transglottal airflow during vowel phonation are analyzed in singers and nonsingers. The waveform, called the flow glottogram, is analyzed by means of inverse filtering, and the spectrum is determined either directly, by submitting the flow glottogram to spectrum analysis, or indirectly, by measuring spectral changes accompanying phonatory changes under conditions of constant vowel articulation. The peak-to-peak amplitude of the flow glottogram pulses shows a strong relationship with the amplitude of the source spectrum fundamental and varies considerably during phonation, presumably depending on the degree of glottal ab/adduction. The negative peak amplitude of the differentiated flow glottogram shows a high correlation with the sound pressure level of the vowel.

Perceptual and acoustic correlates of abnormal voice qualities.

A set of 17 voices representing various voice disorders were presented to a jury of voice experts who rated them on a 5-point scale for each of 28 terms frequently used for describing voices. A statistical treatment of these ratings yielded 5 bipolar factors accounting for 85% of the total variance. Significant correlations were found between four of these factors and certain acoustic data extracted fron long-time-average spectra and fundamental frequency distribution analysis of the same voice sample.

A comparison of contact microphone and electroglottograph for the measurement of vocal fundamental frequency.

Signals from a throat contact microphone or an electroglottograph often are more suited for fundamental frequency measurements with simple analog circuits than the radiated speech signal. This report compares a contact (accelerometer) microphone placed on the neck below the cricoid cartilage and an electroglottograph for measurement of fundamental frequency in connected speech. The advantages and drawbacks of the two methods are discussed.

Pharyngeal constrictions.

From a fiberscope, the tip of which was swung from left to right in the pharynx, cinefilm frames were obtained which showed the cross-sectional shape of pharyngeal constrictions in back vowels. This information was combined with the information offered by X-ray pictures of the same subject phonating the same vowels on a different occasion. The results agree to a reasonable extent with previously published data obtained by different techniques, and support previous hypotheses regarding distance-to-area conversion in the pharyngeal region of the vocal tract.

Acoustic properties of the nasal tract.

Sweep frequency measurements of the transfer function of nasals and nasalized vowels have been found to show a more complex pole-zero pattern than can be predicted with a traditional model of the nasal tract which consists of two parallel tubes coupled to the oral cavities. In this paper, we put forward the hypothesis that the more complex transfer function can be explained with reference to the shunting effect of the sinus maxillares and the sinus frontales. The two maxillar sinuses are situated in the bone symmetrically on the right and left side of the nasal tract. The two frontal sinuses are situated above the nasal tract in the bone of the forehead. These cavities are acoustically coupled to the nasal tract via short channels in the bone. Direct sweep tone data on the transfer function of the nasal tract support this hypothesis.