Speech breathing during reading in women withvocal nodules

This study examined speech breathing patterns during reading bywomen with bilateral vocal fold nodules judged as mildly dysphonic and by women without vocal nodules. Although it might be predictable that the speech breathing patterns of individuals with laryngeal dysfunction will differ from those without laryngeal dysfunction, there is a lack of empirical data to support such assumptions.The results of the current study indicated that glottal airflow was greaterduring reading for the women with vocal nodules and that a larger volume of air was expended both per syllable and per breath group during reading. The rate of speech did not significantly differ between the two groups of women. There was no significant difference for the average duration of the breath groups and no significant difference for the number of syllables spoken per breath group. Additionally, both groups of women demonstrated a similar pattern of inspiratory pause location during the reading. The results suggest that speech breathing patterns associated with dysphonia be examined independently to distinguish specifically the nature of the interaction between the laryngeal dysfunction and the speech breathing pattern. Certainly, more information on how the severity of a voice disorder influences speech breathing is necessary.     

Respiratory response to a decrease in velopharyngeal resistance

Individuals with congenital velopharyngeal impairment generally maintain adequate levels of intraoral pressures during consonant production by increasing respiratory effort. The purpose of the present study was to determine if normal individuals respond to a decrease in velopharyngeal resistance in a similar way. The velar mechanism was perturbed by having subjects voluntarily lower the soft palate during a series of words involving plosive consonants. The pressure-flow technique was used to measure oral pressures, calculate velopharyngeal orifice resistance, and estimate velopharyngeal orifice area. Inductive plethysmography was used to measure breathing volumes associated with the words. The data indicate that, in most instances, intraoral pressure remained at appropriate levels (greater than 3.0 cm H2O) after velar lowering. Speech breathing volume did not change during inspiration, but increased during speech expiration when the velopharyngeal port was open. The difference was statistically significant (p less than 0.01). Duration of the utterance did not change across conditions. A mechanical model was then used to determine how intraoral pressure would be affected by simulating the same conditions in a passive system. The modeling data revealed that pressure would drop threefold. It was concluded that increased respiratory volumes tend to stabilize intraoral pressure when vocal tract resistance is experimentally reduced.     

Application of spectral subtraction method on enhancement of electrolarynx speech

Although electrolarynx (EL) serves as an important method of phonation for the laryngectomees, the resulting speech is of poor intelligibility due to the presence of a steady background noise caused by the instrument, even worse in the case of additive noise. This paper investigates the problem of EL speech enhancement by taking into account the frequency-domain masking properties of the human auditory system. One approach is incorporating an auditory masking threshold (AMT) for parametric adaptation in a subtractive-type enhancement process. The other is the supplementary AMT (SAMT) algorithm, which applies a cross-correlation spectral subtraction (CCSS) approach as a post-processing scheme to enhancing EL speech dealt with the AMT method. The performance of these two algorithms was evaluated as compared to the power spectral subtraction (PSS) algorithm. The best performance of EL speech enhancement was associated with the SAMT algorithm, followed by the AMT algorithm and the PSS algorithm. Acoustic and perceptual analyses indicated that the AMT and SAMT algorithms achieved the better performances of noise reduction and the enhanced EL speech was more pleasant to human listeners as compared to the PSS algorithm.     

Functional Characteristics of a New Electrolarynx “Evada” Having a Force Sensing Resistor Sensor

Electrolarynxes have been used as one of the rehabilitation methods for laryngectomees. Earlier electrolarynxes could not alter frequency and intensity simultaneously during conversation. Recently, we developed an electrolarynx named “Evada” (prototype so far) using a force sensing resistor (FSR) sensor that can control both frequency and intensity simultaneously during conversation. Employing three types of electrolarynxes (Evada, Servox-inton, Nu-vois), this study was undertaken to examine the functional characteristics of Evada for the normal control group and for laryngectomess. Five laryngectomees and five normal adults were asked to express three sentences (declarative sentence, “You stay here.”, interrogative sentence, “You stay here?”, and imperative sentence, “You! Stay here.”) using three types of electrolarynxes. Frequency and intensity changes between the first and last vowels in the three sentences were calculated and analyzed statistically by paired t test. The frequency changes in the interrogative and imperative sentences were more prominent in Evada than in Servox-inton and Nu-vois. The intensity changes in the interrogative and imperative sentences were also more prominent in Evada than in Servox-inton and Nu-vois. Evada controls frequency and/or intensity by having the subject press the control button(s). Therefore, Evada appears to be better at producing intonation and contrastive stress than Nu-vois and Servox-inton.     

Effects of rate and bite block manipulations on kinematic characteristics of children's speech

The purpose of the present study was to investigate kinematic characteristics of the speech of children and adults under three speaking conditions. The effects of requiring subjects to produce speech stimuli were studied as they spoke: in a normal manner; at a faster than normal rate; and while holding a bite block between their molars to restrict mandibular movement. Using a strain gauge monitoring system, superior-inferior lip and jaw movement data were collected from 24 subjects--six in each of three groups of normally developing children and an adult control group. For the normal condition, it was found that net peak velocity (i.e., the sum of the peak velocities of the individual articulators) was quite comparable among the three groups of children and the adults. Net peak velocity increased significantly for all four groups of subjects when they spoke at a fast rate, but it did not increase significantly in the bite block condition. For most measures, there were typically no differences in peak velocity across the various speaking conditions when comparing the three groups of children to one another. In general, articulatory displacement data showed patterns quite similar to those of the peak velocity data. In addition to the displacement and peak velocity data, pilot data are discussed concerning temporal properties of articulatory phases and also concerning maximum, nonspeech articulatory gestures.     

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.     

Movement of the velum during speech and singing in classically trained singers

The present study addresses two questions: (a) Is the action and/orposture of the velopharyngeal valve conducive to allow significant resonance during Western tradition classical singing? (b) How do the actions of the velo-pharyngeal valve observed in this style of singing compare with normal speech? A photodetector system was used to observe the area function of the velopharyngeal port during speech and classical style singing. Identical speech samples were produced by each subject in a normal speaking voice and then in the low, medium, and high singing ranges. Results indicate that in these four singers the velopharyngeal port was closed significantly longer in singing than in speaking samples. The amount of time the velopharyngeal port was opened was greatest in speech and diminished as the singer ascended in pitch. In the high voice condition, little or no opening of the velopharyngeal port was measured.     

Periodic variation in inspiratory volume characterizes speech as well as quiet breathing

Variability in inspired lung volume prior to speech is only partially accounted for by speech-related concerns such as the length and loudness of the planned utterance. Control mechanisms known to influence volume variability in non-speech breathing could potentially account for some of this variability, but only if they operate during speech as well. This investigation was designed to test for the presence of several such mechanisms during reading aloud. Lung volumes were recorded from 5 normal females as they read silently, then aloud. Inspired volumes were correlated with the volumes of the previous and following expirations and with inspiratory duration. Coefficients of variation were calculated for inspiratory volume, duration, and mean flow. Time-series analyses were used to compare periodicity in inspired volume for quiet and speech breathing. Control mechanisms operating during both quiet breathing and reading aloud included slow oscillations in inspired volume and minimized variability in mean flow. Inspired volume prior to speech was weakly but significantly correlated with preceding and following expired volume. It is concluded that some control strategies typical of quiet breathing contribute to volume variability in speech breathing.     

Economy of effort in different speaking conditions. I. A preliminary study of intersubject differences and modeling issues

This study explores the hypothesis that clear speech is produced with greater "articulatory effort" than normal speech. Kinematic and acoustic data were gathered from seven subjects as they pronounced multiple repetitions of utterances in different speaking conditions, including normal, fast, clear, and slow. Data were analyzed within a framework based on a dynamical model of single-axis frictionless movements, in which peak movement speed is used as a relative measure of articulatory effort (Nelson, 1983). There were differences in peak movement speed, distance and duration among the conditions and among the speakers. Three speakers produced the "clear" condition utterances with movements that had larger distances and durations than those for "normal" utterances. Analyses of the data within a peak speed, distance, duration "performance space" indicated increased effort (reflected in greater peak speed) in the clear condition for the three speakers, in support of the hypothesis. The remaining four speakers used other combinations of parameters to produce the clear condition. The validity of the simple dynamical model for analyzing these complex movements was considered by examining several additional parameters. Some movement characteristics differed from those required for the model-based analysis, presumably because the articulators are complicated structurally and interact with one another mechanically. More refined tests of control strategies for different speaking styles will depend on future analyses of more complicated movements with more realistic models.     

An acoustic analysis of fluctuations in the voices of normal adult speakers across three times of day

The purpose of this study was to determine the amount of variation for several vocal parameters across three times of the day (morning, noon, and afternoon). Connected speech samples from normal adult males (N = 10) and females (N = 10) were recorded during morning, early afternoon, and late afternoon. Results showed that males produced a statistically significant increase in speaking fundamental frequency (SFF) from morning to afternoon. Females did not demonstrate a statistically significant change in SFF across the three time periods. Vocal amplitude did not change significantly for either group. The SFF variability was higher for the females than for the males. Analysis of individual data revealed that the patterns of vocal change across the three times of day were not consistent among the subjects.     

Effects of speaking style on speech intelligibility for Mandarin-speaking cochlear implant users

Cochlear implant (CI) users' speech understanding may be influenced by different speaking styles. In this study, speech recognition was measured in Mandarin-speaking CI and normal-hearing (NH) subjects for sentences produced according to four styles: slow, normal, fast, and whispered. CI subjects were tested using their clinical processors; NH subjects were tested while listening to a four-channel CI simulation. Performance gradually worsened with increasing speaking rate and was much poorer with whispered speech. CI performance was generally similar to NH performance with the four-channel simulation. Results suggest that some speaking styles, especially whispering, may negatively affect Mandarin-speaking CI users' speech understanding.     

Paradoxical vocal fold movement: A case report

We present a case of one patient with respiratory stridor that was resolved by speech therapy. Paradoxical vocal fold movements were observed by flexible fiberoptic videolaryngoscopy in this patient during episodes of wheezing and dyspnea. Otherwise, normal vocal fold movement was observed in normal conditions of breathing (out of the crisis) and during phonation. Many different terms have been used to describe this entity in the literature, and it is crucial that clinicians recognize the subtle signs of functional stridor. Paradoxical vocal fold motion has to be considered as an important cause of respiratory disease. Its recognition and treatment are discussed in this report.     

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.     

Speech performance of adult cantonese-speaking laryngectomees using different types of alaryngeal phonation

The purpose of the present study was to compare the speech performance of four types of alaryngeal phonation-electrolaryngeal (EL), pneumatic artificial laryngeal (PA), tracheoesophageal (TE), and standard esophageal (SE) speech-by adult Cantonese-speaking laryngectomees. Subjective ratings of (1) voice quality, (2) articulation proficiency, (3) quietness of speech, (4) pitch variability, and (5) overall speech intelligibility were given by eight naive individuals who had no prior experience with any form of alaryngeal speech. Results indicated that SE and TE speech was perceived to be more hoarse than PA and EL speech. EL speech was associated with significantly less pitch variability, and PA speakers produced speech with the least amount of perceived noise. However, articulation proficiency and overall speech intelligibility were found to be comparable in all four types of alaryngeal speakers.     

Breathing muscle activity and subglottal pressure dynamics in singing and speech

Previous studies have indicated that the diaphragm may contribute to the accomplishment of the quick and precise subglottal pressure changes required during singing. The present investigation compares data collected from simultaneously recorded electromyograms from breathing muscles and transdiaphragmatic pressure during singing as well as during nonsense and emphatic speech.     

Regional Chest Wall Volume Changes During Various Breathing Maneuvers in Normal Men

Purpose: The purpose of this study is to investigate the regional chest wall volume changes during various breathing maneuvers in normal men with an optical reflectance system (OR), which tracks reflective markers in three dimensions. Methods: Chest wall volume was measured by the OR system [V_L(CW)], and lung volume was measured by hot wire spirometry [V_L(SP)] in 15 healthy men during quiet breathing (QB), during breathing at a rate of 50 tidal breaths/min paced using a metronome (MT: metronome-paced tachypnea), and during a maximal forced inspiratory and expiratory maneuver (MFIE maneuver). Results: There were few discrepancies between V_L(CW) and V_L(SP) for QB and MT. In the MFIE maneuver, however V_L(CW) was often underestimated compared with V_L(SP), particularly during forced maximal expiration, because of pulmonary rib cage volume changes. Furthermore, the regional chest wall volume changes were affected by breathing maneuver alternation. In the pulmonary and abdominal rib cage, inspiratory reserve volume was larger than expiratory reserve volume, respectively, and in the abdomen, expiratory reserve volume was larger than inspiratory reserve volume. Conclusion: Alternation of breathing maneuvers affects regional chest wall volume changes.     

Acoustic analysis of the speaking voice after thyroidectomy

Voices of 47 female patients were analyzed before and after thyroidectomy, with preservation of the recurrent and superior laryngeal nerves and normal vocal fold motility during the observation period. A mean decrease of the speaking fundamental frequency (SFF) of 12 Hz was found on day 4; in 8 patients the postoperative vocal pitch was more than 2 semitones lower. The distance between the highest and lowest F₀ during speaking was diminished (speech was more monotone) and the vocal jitter was elevated. In the frequency spectrum, there was a diminished prominence of the harmonics. The other spectral parameters (as the slope of the spectrum and the H1/H2 ratio) were unchanged. All changes had disappeared the fifteenth day, except for a lower SFF (>2 semitones) in 2 cases. It is concluded that after normal dissection of the laryngeal nerves, and in the absence of vocal fold paresis, other reasons for voice changes immediately after thyroidectomy remain: alterations in the neck muscles, in the laryngeal mucosa, and in the patient's general condition. Although the effects seem limited and of short duration, knowledge of them is helpful when informing the patient before thyroid surgery.     

What's so special about singers?

Research on singers' breathing, phonation and articulation patterns during singing is reviewed and comparisons are made with typical speech patterns. It is found that singers' and nonsingers' use of the voice differ in several respects. The reasons for these differences are discussed and explanations are proposed referring to the special demands raised on singers with respect to economization of vocal effort and flexibility of phonation.     

The effects of diazepam on intrinsic laryngeal muscle activation during respiration and speech

Electromyographic recordings of intrinsic laryngeal muscles were made during respiration, phonation, speech, and swallow in three subjects in two conditions: with and without intravenous administration of 5 mg of diazepam. The mean activity in microvolts of the thyroarytenoid and cricothyroid muscles was measured during respiration and the percentage increase over resting levels during inspiration, expiration, swallow, phonation, and speech. All subjects demonstrated significant (p ≤ 0.001) reductions in mean activity during respiration with diazepam. Significant (p ≤ 0.001) diazepam, subject, and subject by diazepam interactions were found in the percentage increase in muscle activation on each task. In one subject muscle activity consistently decreased, while in the other two subjects it consistently increased with diazepam. Although all had significant muscle relaxant effects, individuals differed in their diazepam responses during muscle activation. These differences may relate to a subject's age.