Laryngeal Adjustments Research Articles

Speech-Related Reaction Times of Stutterers and Nonstutterers

Speech-related reaction time measures (laryngeal premotor and adjustment time for /a/, labial initiation and physiological voice onset time for /pa/) and fluency-related measures (number of stutterings, number of normal disfluencies, and time needed to complete an oral reading) of 24 stutterers and a like number of nonstutterers were assessed to determine their diagnostic discriminative power. Discriminant analysis showed that stutterers were most effectively differentiated from normally fluent speakers by the total number of stutterings and normal disfluencies during oral reading and by the duration of laryngeal adjustments prior to cued phonation. Factor analysis revealed that the fluency failure and reaction time measures clustered independently for both stutterers and nonstutterers. These findings suggest that both fluency failures and the duration of laryngeal adjustment time are useful diagnostic measures for discriminating stutterers from those who are normally fluent.

内喉頭筋の神経終末の形態学的観察

The larynx performs fine adjustments as the eye balls do. Motions of the vocal folds are, therefore, supposed to be regulated by the afferent and efferent innervation more precisely than many other skeletal muscles. The purposes of this paper were to investigate morphological features of the laryngeal muscles, muscle spindles and sensory nerve endings in different species which might explain the ability of fine laryngeal adjustments. Histochemical studies of muscle fibers and morphometrical analyses of subneural apparatus at the neuromuscular junctions of the canine larynges showed that the intrinsic laryngeal muscles consisted of three types of muscle fibers : type 1, 2 A and 2 C. Each type had a specific subneural apparatus. The postnatal differentiation of the muscle fibers of the larynx of rats was completed prior to the development of the subneural apparatus. The muscle spindles in the intrinsic muscles of human larynges contained rich collagenous fibrils in a narrow periaxial space. The density of muscle spindles was low. The same morphological features of the muscle spindle were also observed in monkeys. The sensory nerve endings on the intrafusal fibers were not of the annulo-spiral type, which had been generally observed in mammalian muscle spindles, but of a varicose type. The sensory nerve endings on the laryngeal muscles were richer more multiform in human beings than in monkeys. It is considered that a few muscle spindles regulate laryngeal motions in cooperation with rich sensory nerve endings

発話時の喉頭調節

There is general consensus that the larynx is the organ of voice. Less well recognized is the role it serves in speech production. Recently, it has been shown that the larynx is a major contributor to articulatory adjustments. These laryngeal adjustments are produced by coordinated activities of the intrinsic and extrinsic muscles of the larynx. Since the introduction of a fiberscopic and electromyographic techniques to the field of experimental phonetics, the nature of laryngeal adjustments in different languages has been explored in more detail than heretofore was possible. Further, the use of different types of glottography and computer-controlled image analysis opened a new scope in laryngeal physiology. In the present paper, using a combination of recently developed experimental techniques, the physiological correlates of each the four basic features of laryngeal articulatory adjustments are discussed. The basic features of the laryngeal articulatory adjustments addressed consist of : 1) abduction-adduction of the vocal folds with special reference to voicing distinctions;2) constriction of the false vocal fold and other supraglottal structures related to whispering and laryngealization gestures;3) changes in the length and thickness of the vocal folds with respect to prosodic control; and4) vertical movements of the larynx.

Laryngeal adjustments or subglottal pressure? Studies on sentence stress production with excised human larynges

We used excised human larynges to produce F o changes perceived as stress in two ways: by manually rotating the cricothyroid articulation and by changing subglottal pressure. According to our results, it is possible to bring about a perceivable stress by either of these mechanisms. However, an increase in vocal fold tension also caused a marked rise in subglottal pressure, suggesting that in normal speech there is considerable interaction between these mechanisms. Rotation produced larger F o changes than considerable pressure changes alone.

有声，無声の音声学的変異の喉頭調節

The role of laryngeal adjustments for allophonic variations of voicing in Japanese — vowel devoicing and intervocalic /h/ voicing — was investigated using laryngeal electromyography and fiberscopic endoscopy. The results indicated that the vowel devoicing was accompanied by EMG activity patterns of the posterior cricoarytenoid and interarytenoid, which were different from those for fully voiced vowels, causing the glottis to be wide open. This suggested that vowel devoicing mainly reflects a kind of free variation at a higher level than the EMG signals. In contrast, the voicing of intervocalic /h/ occurred while the glottis remained as wide as it did for voiceless /h/ or /s/ with comparable EMG patterns of those muscles, despite the presence of vocal fold vibrations. Therefore, it may be that this latter phenomenon is chiefly dependent on some other condition at the level of the glottis.

Aerodynamic and acoustic characteristics of the voicing distinction in electronic larynx speech

Speech attributes that depend primarily on laryngeal adjustments in normal speech can also be produced by skilled alaryngeal speakers. For example, listeners reliably perceive the consonant voicing distinction in the production of good electronic larynx speakers. In most cases, electronic larynx speech is produced with a continuous sound source regardless of the voicing features of consonants. Therefore, voicing distinctions are evidently not produced by systematic control of voice timing relative to consonantal closure. It has been suggested that electronic larynx speakers use some alternative strategies, such as markedly higher intraoral pressure for voiceless consonants than for their voiced cognates, producing different acoustic patterns for different voicing features. In this study, acoustic and intraoral pressure measurements were made during multiple repetitions of nonsense syllables produced by laryngectomees and normals with and without (transcervical‐type) electronic larynges. Different aerodynamic and acoustic patterns pertaining to voicing distinctions in normal and electronic larynx speech were observed. Some specific mechanisms in electronic larynx speech will be discussed. [Work supported by NIH Grant NS13870.]

Symptom improvement of spastic dysphonia in response to phonatory tasks.

It has been acknowledged that for many patients with spastic dysphonia, reflexive phonation remains essentially free of the spasticity that characterizes this disorder. The purpose of this paper is to document the extent to which various phonatory tasks change the patient's voice. We retrospectively reviewed 37 patients with spastic dysphonia evaluated at the Center for Communication Disorders of Lenox Hill Hospital, New York, between 1977 and 1981. The patients' responses to various phonatory tasks were observed. These tasks were grouped into the following ten categories: noncommunicative vocalization, primitive communication, speech superimposed on noncommunicative phonation, communicative phonation with varied mode of vocal fold vibration, normal communicative phonation with unusual pitch, normal communicative phonation with unusual emphasis, normal communicative phonation with normal laryngeal adjustments, use of the vocal folds in an artistic manner, speech in which normal auditory feedback was eliminated, and speaking with whisper which was not associated with vocal fold vibration. The results are summarized as follows: 1) whispered speech always resulted in an improvement of the symptom, in most cases markedly; 2) there was a tendency for a task that was more effective in reducing spasticity to be reduced in communicative function; 3) there was a tendency for a task that was more effective in reducing the spasticity to deviate more from the normal mode of phonation; and 4) there were some patients in whom an improvement occurred with elimination of auditory feedback.

Laryngeal adjustments in stop and fricative production

A computerized pulsed ultrasound system was used to study the dynamics of laryngeal abduction during obstruent production. Subjects produced the consonants /s/ and /t/ in a /tɛCɛt/ context at two rates, with either the first or second vowel stressed. Preliminary results indicate that the time from offset of the first vowel to the maximum laryngeal opening was positively related to oral closure or approximation duration. However, the maximum opening of the gestures associated with the production of /s/ occurred closer to vowel offset than those for /t/ in comparable conditions. In addition, the interval from vowel offset to maximum opening velocity was found to vary as a function of stress and consonant. The time to maximum velocity was shorter for the gesture associated with /s/ than for /t/ and shorter for consonants following a stressed vowel than for those preceding stressed vowels. These aspects of laryngeal displacement and timing will be discussed in terms of interarticulator organization.

Laryngeal adjustments in Japanese voiceless sound production

As part of a series of investigations on the production of sequence of unvoiced sounds in different languages, the current experiment was conducted using the combined techniques of photo-electric glottography, fiberoptic filming and laryngeal electromyography. Particular attention was paid to devoiced vowel production in various voiceless consonantal environments including geminates. The data show that the glottal opening gesture during a voiceless sequence containing a devoiced vowel is characterized by a monomodal pattern, unless the vowel occurs between a voiceless fricative and a geminated one, such as /siQs/, where a bimodal pattern may occur. The movement results also suggest that the velocity and size of the glottal opening gesture vary according to the nature of the adjacent voiceless obstruents. The speed of the opening phase is slow when a stop precedes the vowel, and fast when a fricative precedes it. The peak glottal opening attained during the devoiced vowel is larger when a fricative either precedes or follows than when the vowel is surrounded on both sides by single or geminated stops. Furthermore, it is revealed that the peak velocity of the initial opening gesture occurs at almost the same time in relation to the voicing offset of the preceding vowel, regardless of the properties of the surrounding voiceless obstruents and, thus, irrespective of variations in the magnitude of velocity and opening size.

Laryngeal adjustments in the production of consonant clusters and geminates in American English

The glottal opening gesture and its timing control in various sequences of voiceless obstruents were investigated by the combined techniques of electromyography, photo-electric glottography, and fiberoptic endoscopy. The results obtained at both electromyographic and movement levels revealed that the glottal opening gesture is characterized by a one-, two-, or more-than-two-peaked pattern in a regular fashion according to the phonetic nature of the voiceless segments: each voiceless obstruent or geminate accompanied by aspiration or frication noise tends to require a single separate peak of the opening gesture, while an unaspirated stop embedded in a voiceless environment can be produced within the opening gesture attributed to an adjacent aspirated stop or fricative. Such an independent opening gesture of the glottis for the production of voiceless aspirated stops or voiceless fricatives even in sequentially unvoiced contexts can be interpreted as assuring the aerodynamic requirements for turbulent noise production during the aspirated stop or fricative segment.

Laryngeal adjustments in the production of the fricative consonants and devoiced vowels in Japanese.

The role of laryngeal adjustments for phonetic variations of voicing in Japanese--vowel devoicing and intervocalic /h/ voicing--was investigated using laryngeal electromyography (EMG) and fiberoptic endoscopy. The results indicated that the vowel devoicing was accompanied by EMG activity patterns of the posterior cricoarytenoid and interarytenoid different from those for fully voiced vowels, causing the glottis to be wide open. In this respect, it may be concluded that vowel devoicing mainly reflects a kind of free variation at a higher level than the EMG signals. In contrast, the voicing of /h/ occurred while the glottis remained as wide as it did for voiceless /h/ or /s/ with comparable EMG patterns of those muscles, despite the presence of vocal fold vibrations. Therefore, it may be that this latter phenomenon is chiefly dependent on some other condition at the level of the glottis.

Laryngeal Activity in Icelandic Obstruent Production

Laryngeal activity in the production of voiceless obstruents and obstruent clusters in Icelandicwas investigated by the combined techniques of transillumination and fiberoptic filming of the larynx. Contrasts of preaspirated, unaspirated, and postaspirated voiceless stops were found to be produced basically by differences in laryngeal-oral timing. In clusters of voiceless obstruents, one or more continuous laryngeal opening and closing gestures occurred depending on the segments in the cluster.Peak velocity of glottal abduction was higher for fricatives than for stops. This, and other differences in laryngeal adjustments and interarticulator timing between stops and fricatives, are most likely due to different aerodynamic requirements for stop and fricative production. The present results further question the usefulness of timeless feature descriptions for modeling speech production.

Laryngeal adjustments in the production of voiceless unaspirated, aspirated, and glottalized stops

Two talkers produced utterances that contained one of three classes of voiceless stops (unaspirated, aspirated, and glottalized stops), and simultaneous electromyographic recordings were obtained from three intrinsic laryngeal muscles (interarytenoid, lateral cricoarytenoid, and vocalis). During the production of unaspirated and aspirated stops, the interarytenoid and vocalis act in concert, inactive for the voiceless closure interval and active for voice onset following stop release. Both are markedly suppressed during closure for aspirated stops, and their activity rises (sharply in the case of the interarytenoid) for subsequent voice onset. The lateralis is uniformly inactive throughout closure and release of these two categories. By contrast, it is lateralis and vocalis that act in parallel for ejectives: a marked peak occurs in lateralis and vocalis activity during the voiceless closure interval, presumably for achievement of tight glottal closure. The interarytenoid is inactive during oral closure for ejectives and becomes active only as lateral cricoarytenoid and vocalis activity subsides following oral release. [Work supported in part by NINCDS and NIDR.]

Laryngeal adjustments in Japanese voiceless sound production

As part of a series of investigations on the production of sequences of unvoiced sounds in different languages, the current experiment was conducted using the combined techniques of photoelectric glottography, fiberoptics, and electromyography. Particular attention was paid to devoiced vowel production in various voiceless consonantal environments including geminates. The movement data show that the glottal opening gesture during a voiceless sequence containing a devoiced vowel is characterized by a monomodal pattern, unless the vowel occurs between voiceless fricatives. The results also suggest that the velocity and size of the glottal opening gesture vary according to the nature of the adjacent voiceless obstruents. The speed of the opening phase is slow when a stop precedes the vowel, and fast when a fricative precedes it. The peak glottal opening during the devoiced vowel is larger when a fricative either precedes or follows it, and smaller when the vowel is surrounded on both sides by single or geminated stops. [Work supported by NINCDS and BRSG.]

Some notes on the physiology of speech production.

Three different topics in speech research are discussed from the point of view of the physiology of the speech production mechanism. Concerning the problem of the laryngeal adjustments for the voicing distinction, fairly clear physiological evidence has been obtained about the abduction-adduction dimension of the glottis, while the tenseness feature of the vocal folds is still to be examined. Detailed analysis of the articulatory movements in syllable repetition is considered to be a promising approach for the study of articulatory dynamics in both normal and pathological cases. Neurophysiological studies of the cerebro-cerebellar communication system as a control mechanism of skilled voluntary movements should be referred to in the study of motor control of speech production.

Contrasting sounds in the upper male voice

Four sounds were contrasted in the upper male voice. The sounds were identified as follows: (1) falsetto; (2) head tone; (3) pharyngeal voice; (4) operatic head voice. All sounds were sung by a tenor on the vowel /a/ at a pitch level of A4, 415 Hz. Spectrographic analyses were performed to determine what physiological relationships might be inferred among the sounds. The length of time the singer was able to sustain each sound was tested in order to gain information concerning the relative air flows. The results show that the pharyngeal voice and operatic voice have much more energy in the high partials and have much lower rate of air flow. This evidence indicates that these two sounds are characterized by much more complete closure of the glottis than is exhibited in the other two sounds. It is concluded that the four sounds are produced by only two different laryngeal adjustments. Acoustical differences accounting for differentiation of sounds produced by the same laryngeal setting are discussed. A recommendation is made concerning the pedagogical use of registers and suggestions are made for further research.

Laryngeal adjustments in stutterers

Simultaneous recordings of voice and photoelectric glottogram during the speech production by stutterers were made. The subjects were asked to produce as quickly as possible each of 36 different meaningful words in response to a visual stimulus. The results revealed that some cases of part‐word (word initial voiceless stop) repetitions were accompanied by one or two extra opening gestures corresponding to the repeated aspiration noises. Similar trial‐and‐error types of the glottal movement were also detected even during silent delayed response time in some other cases which were auditorily judged as fluent. As for the production of the words begun with voiced sounds, unnecessary opening gestures prior to the vocalization for the initial voiced segment were sometimes observed, regardless of the judgements on its fluency and/or on the length of its latency. These findings suggest that at least this type of stuttering is linked to temporal disruption of the precisely controlled abducting and adducting gestures of the glottis, which are indispensable to fluent speech production. [Work supported by NINCDS and BRSG.]

Laryngeal adjustments during American English consonant cluster production

The glottal opening gesture and its timing control in clusters of voiceless obstruents was investigated by use of electromyography. Two distinct peaks in the abductor muscle (PCA) activity curve were found for /sk/ sequence when a word boundary intervened. but only one for the same sequence without the boundary. For the geminate combination /ss/ or /kk/, the abductor activity pattern was characterized by one single peak surrounded by gradual slopes, although a word boundary intervened within the cluster. In the case where word final /k/ was followed by word initial /s/ or /sk/, however, the abductor muscle showed one broad continuous but rather small peaked curve during the whole cluster. These results. together with transillumination and fiberoptic data, suggest that each voiceless obstruent characterized by aspiration or frication noise tends to require a single separate opening gesture, while an unaspirated stop in voiceless environment can be produced within the opening gesture attributed to the adjacent aspirated stop or fricative. [Work supported by NINCDS and BRSG.]

Laryngeal adjustments in Japanese word accent

The role of the intrinsic laryngeal muscles in accomplishing various accent types in Japanese was studied. Specifically, the electromyographic activities of the posterior cricoarytenoid (PCA) and the thyroarytenoid (VOC) were investigated in comparison with that of the cricothyroid (CT). It was revealed that the PCA activity for the voiceless stops or affricates following the first mora with accent kernel was significantly smaller than that for those in the second mora not preceded by accent kernel, regardless of whether or not this second mora has accent kernel. The results were in good agreement with those of fiberoptic observation. The glottal width was always larger for the latter group. The VOC showed activity patterns similar to the CT, generally peaking for the accent kernel. However, the VOC activity tended to decline more rapidly than the CT after the peak. It was also suggested that VOC activity was related not only to the realization of accent but to various segmental features such as glottalization of the word initial vowel or voicelessness of the phonetic segment. [Work supported by NIH NS‐13870.]

The Adams and Reis observations revisited

This experiment was designed as a replication of the Adams and Reis (1971, 1974) experiments, which posited a direct relationship between frequency of stuttering and the number of “off-on” laryngeal adjustments during speech. Twenty adult stutterers read two prose passages equivalent in length, word length, and semantic content. The first passage contained a normal distribution of syllable-initial voiced and voiceless consonants whereas the second contained only voiced phonemes. The results demonstrated significantly greater stuttering during reading of the all-voiced passage ( P⩽0.05). These results did not confirm the earlier observations of Adams and Reis and mitigate the hypothesized relationships between stuttering frequency and “off-on” laryngeal adjustments.