Robert E. McGlone

Peak magnitudes of supraglottal air pressure associated with affricated and nonaffricated stop consonant productions in Hindi

Peak magnitudes of supraglottal air pressure, under a variety of conditions, were obtained during stop productions from three normal adult speakers of Hindi. The stops were produced in CVCVC nonsense utterances which were embedded in the carrier phrase, “ye—hae.” Significant differences in peak magnitudes were found as a function of the place of articulation of a stop and its position in an utterance. Peak magnitudes were always significantly higher for unvoiced stops than for voiced stops. Aspirated stops, in general, showed higher peak magnitudes than unaspirated stops, but a significant level of difference in peak magnitudes was reached only under voiced conditions. Differences in peak magnitudes as a function of stress were significant under voiced conditions; under unvoiced conditions the differences were less pronounced.

Supraglottal air pressure during a valsalva maneuver

Supraglottal air pressure (P10) is defined as the build‐up of air pressure within the oral cavity as a result of articulatory resistance to pulmonic air flow. Two major assumptions are inherent in this definition; (1) a column of air moves through the vocal tract supplied by a pulmonic source; (2) P10 results directly from a partial/complete resistance to this air column. The present study was a test of these two assumptions. Subjects repeated VCV syllables containing the cognate pairs /p,b/, /t,d/, and /s,z/ during a valsalva maneuver (absence of pulmonic air flow). Peak measures of P10 were obtained from the consonant productions. Results indicated that even in the absence of pulmonic air flow, the oral pressures generated were similar to those recorded for normal speech. Moreover, the voice‐voiceless distinction typical of normal speech was observed for the valsalva productions. These results indicate that we may need to re‐evaluate present descriptions of P10, especially in terms of the role of the pulmonic air source. Also, it may be that P10 is not merely a result of laryngeal/articulatory resistance, but is phoneme specific.

Further observations of intraoral pressures during sentence production

The purpose of this study was to obtain further information related to the changes that occur in intraoral pressures (tongue and air) as a result of increased vocal intensity caused by masking auditory feedback. Four males repeated sentences containing the /t,d,n/ consonants, during which different levels of masking were introduced binaurally. No significant differences in either intraoral pressure as a function of change in the masker level were noted. Furthermore, no systematic differences between /t/, /d/, and /n/ were observed for tongue pressures. These results are contradictory to previous studies; the contradictions were related (but not totally) to the speech samples used (the present study incorporated sentence materials whereas previous studies used nonsense syllables). Left‐right dominance associated with tongue pressure was also noted.

Relation of Intraoral Air Pressure to Oral Cavity Size

The purpose of this study was to investigate whether the size of the oral cavity of a speaker was related to pressures occurring in the mouth during speech. Of the three previous studies that considered size and pressure, two report a positive relationship and one found no relationship. Six young adult males were selected as subjects on the basis of cavity dimensions obtained from measurements of lateral headplates and molar widths. Each repeated CV and VC syllables composed of /t/, /d/ and /n/, and /i/ and /a/. These syllables were produced at two relative intensity levels and at two rates of utterance. Pressure measures obtained during repetition of the speech sample showed no systematic trends associated with cavity size, different vowels, rates of utterance, or syllabic position. Mean pressure differences were found between consonants and relative intensity levels.

Intraesophageal Pressure during Syllable Repetition

Intraesophageal pressure was investigated as a possible indirect indicator of subglottic pressure in a dynamic speech situation. Five male subjects repeated the syllable /pʌ/ at rates of 1/sec and 4/sec, for 4 sec. Balloon length, diameter, position in the esophagus, and volume of air in the balloon were systematically varied. Of interest was the magnitude of change in intraesophageal pressure values that occur during any trial and the repeatability of the pressure measures in relation to the various experimental factor combinations. It was found that intraesophageal pressure values varied as lung volume changed; increasing as lung volume decreased. Also, variability between repeated trials was so large that the technique of intraesophageal pressure measurement appeared not to yield useful data. Amplitude of the pressure pulses associated with syllables repeated once per second appeared to interact with base pressure; decreasing as base pressure increased. No pressure pulses were found associated with syl...

Identification of Vocal Register Shift in a Helium‐Rich Atmosphere

Three methods were used to identify where subjects changed from model to falsetto register while breathing either air or a helium‐oxygen mixture. Six male subjects sustained phonations in discrete semitone steps up and down the scale twice each way under both gas conditions. They notified the investigators when a shift in registers occurred. Recordings were made, randomized, and played to judges instructed to locate the shift. The recordings also were subjected to spectrographic analysis. Results showed subjects were slightly more constant at place of shift when breathing HeO2 than air. Judges also agreed with the subjects more frequently for phonations under the helium condition. No systematic differences except frequency could be found on the spectrograms of the phonations around the shift. Implications, from these results, of how registers are produced will be presented.

Transglottic Air Flow Related to Selected Parameters of the Voice

This study was concerned with the relationship of air flow to systematic changes of vocal pitch, vocal intensity, and voice register. Nine young adult women with no previous vocal training were selected as subjects. Their respective pitch ranges were determined for the modal and upper registers and these ranges were divided into 10% segments. Vocal intensity ranges at each of these pitch levels were established and also divided into 10% segments. Air‐flow measures were obtained from respirometric recordings made as each subject sustained the vowel /a/ for 4 sec at each intensity level for each pitch segment in both registers Results of these measurements showed that a progressive increase in air‐flow accompanied increases in vocal intensity in both the modal and upper registers. A progressive increase in air flow also was found as vocal pitch was increased in the modal register. No such relationship was found in rite upper register.

Auditory Thresholds in Adrenal Cortical Insufficiency

It has been previously shown that patients with untreated adrenal cortical insufficiency (ACI) exhibit decreased detection thresholds for taste and smell. These thresholds return to normal after treatment with carbohydrate‐active steroids (CAS) is instituted. The purpose of the present study was to compare auditory detection thresholds in eight patients with ACI, aged 14–57, with those in 25 normal volunteers, aged 18–61. Sinusoidal tones of different frequencies were presented by a calibrated oscillator, attenuator, earphone system, and thresholds determined by the method of limits. Auditory detection thresholds in patients with ACI were significantly lower than those in normal subjects over most of the frequency range, but especially in the region 1000–2000 Hz. Increased detection sensitivity was found in all patients, irrespective of age; it appeared independent of changes in extracellular sodium or potassium. Decreased auditory thresholds returned to normal in all patients after CAS therapy was reinst...