Subjective evaluation of voice and working conditions and phoniatric examination in kindergarten teachers.

AIMS: This study evaluated the prevalence of voice problems in kindergarten teachers and investigated some background factors affecting vocal health. METHODS: One hundred and nineteen female kindergarten teachers volunteered by responding to an Internet questionnaire on voice habits, voice symptoms, and the amount of negative impact various working conditions may have on their voices. Phoniatric examination was carried out with a rigid laryngoscope. RESULTS: Of the subjects, 71.5% reported frequent strain on the voice (monthly or more often), and 56.3% reported hoarseness without infection. Eighty-six percent reported that when their voice got tired during the working day it recovered quite well, well or remarkably well by the next day. Noise at work was considered most detrimental to the voice. Clear organic findings were observed in 10.9% of the cases and did not correlate with subjective voice symptoms. CONCLUSIONS: The results confirmed earlier findings that a remarkable number of kindergarten teachers suffer from voice problems and consider noise in the environment especially to be harmful to their voices. However, the majority reported recovering well from vocal symptoms. Further studies are needed on individual speech habits, working day-related voice evaluation, recovery time and work-environmental factors. A follow-up is warranted to identify the main factors leading to voice problems.

Health-related quality of life of children with specific language impairment aged 8-11.

OBJECTIVE: To evaluate, in a clinical sample of children with a diagnosis of specific language impairment (SLI), the health-related quality of life (HRQoL). SUBJECTS AND METHODS: Fifty-five children, aged 8-11 years, filled out a generic HRQoL questionnaire, 17D, and another questionnaire about school and rehabilitation. The HRQoL comparison group was a sample of 244 typically developing schoolchildren. RESULTS: Response rate was 86%. Of the respondents, 80% were male. The total 17D score of the subjects did not differ from that of controls. The 17D profiles of the groups differed on several dimensions, but significant differences emerged only on the dimensions concerning speech, where the study group was worse off, and sleep, where the controls reported more problems. Respondents with low verbal IQ reported more distress. The vast majority of respondents were in special education or received extra educational support and one-third were still having speech therapy. CONCLUSION: In this clinical sample, despite the persisting need for extra support, the overall well-being of children with SLI was at age level. Still, some differences existed, and HRQoL measurement may prove a good tool for professionals to find those children with SLI at risk for diminished well-being and for later problems.

Health-related quality of life of adults with childhood diagnosis of specific language impairment.

OBJECTIVE: The health-related quality of life (HRQoL) of adults with childhood diagnosis of specific language impairment (SLI) was evaluated. PATIENTS AND METHODS: Fifty-two patients with a childhood diagnosis of SLI were asked to fill out the 15D-HRQoL questionnaire. The patients were selected from a hospital setting from psychological examination reports showing a below-average verbal intelligence quotient (VIQ) and a normal performance intelligence quotient (PIQ). The 15D was completed adequately by 33 patients (response rate 63.5%). The results were compared with those of age- and gender-matched controls. RESULTS: The total 15D score of the study group was lower than that of population controls, but the difference was not statistically significant. The study group performed significantly worse on the dimensions of speech, usual activities, mental function and distress. Gender or PIQ in childhood was not correlated with the 15D scores or dimension scores in adulthood. Childhood VIQ was associated with the dimensions of mental function (p < 0.01) and usual activities (p < 0.05). CONCLUSION: Our results support earlier findings that SLI affects the entire life span. Identification of prognostic factors and a prolonged follow-up of SLI patients could improve the QoL of these patients.

Specific language impairment in childhood is associated with impaired mental and social well-being in adulthood.

To study the possible influence of childhood language impairment on adult life and well-being, 35 persons with a mean age of 34 years filled out two questionnaires. Compared with the general population, subjects more often lived with parents, and were pensioned. Only a few reported having literacy problems, but over 40% had difficulty in finding words and remembering instructions. Childhood performance IQ was associated with education and word-finding difficulties, and verbal IQ with difficulties in remembering instructions. Health-related quality of life was related to literacy skills, finding words, and remembering instructions. In conclusion, adults with childhood language impairment differ markedly from the general population. Problems in expressing themselves and receiving information affect their well-being the most. Childhood performance seems to have some prognostic value for language-based problems in adulthood.

The effect of postmenopause and postmenopausal HRT on measured voice values and vocal symptoms.

OBJECTIVES: To study the effect of postmenopause and postmenopausal hormone replacement therapy (HRT) on the measured fundamental frequency (F0) and sound pressure level (SPL) of sustained phonation and speaking voice samples and on subjective vocal/laryngeal symptoms. METHODS: Forty-three postmenopausal women (mean age 51.6) were divided into three groups: a group with no HRT, an estrogen group (daily oral dose of 2 mg of estradiol valerate), and an estrogen-progestin group (daily oral dose of 2 mg of 17-B-estradiol and 1 mg of northisterone acetate). Voice measurements were made before and after 1 year of treatment. Subjective symptoms were registered using a questionnaire. RESULTS: The mean F0 and SPL decreased significantly in the group with no HRT in spontaneous speech and reading samples as did SPL in the normal phonation sample. In both groups with HRT, the mean F0 decreased significantly only in the spontaneous speech sample and the decrease was smaller than in the group with no HRT. The mean SPL decrease in the estrogen group was significant in the normal phonation sample while in the estrogen-progestin group it was significant in both the normal phonation and the reading sample. The number of subjective symptoms was smallest in the estrogen group. CONCLUSIONS: The changes in the measured voice values and the subjective symptoms experienced suggest that at least the early postmenopausal years are associated with vocal changes and that HRT counteracts this phenomenon. This seems to be more pronounced with estrogen than with a combination of estrogen and progestin.

Fragile X speech phonology in Finnish.

Fragile X syndrome is a recently discovered relatively common syndrome linked with an anomaly of the X chromosome and causing handicaps of cognitive development especially in males. In the present phonological analysis we will discuss the sound patterns of two Finnish fragile X speakers, a five (borderline intelligence)- and an eight (mildly mentally retarded)-year-old boy. The fragile X syndrome is not necessarily linked with any anomalies of speech organs. The subjects could produce all Finnish speech sounds in isolated test words. However, in the present samples of connected speech they exhibited general dysphonology. What is noteworthy is that their phonological error patterns resembled each other to a great extent. Among the common features were the tendencies to substitute and omit phonemes. As for vowels, our results showed about one-half of the errors to be omissions. Labiality and quantity oppositions were quite resistant to substitution. Most substitution errors of place of consonants occurred in dentals. As for the feature of manner, /r/ and /s/ were the phonemes most prone for substitution. A tendency toward spirantization or /h/ sation was common for both patients. The number of additions was clearly lower than has been reported for English-speaking developmentally dyspraxic children and also for Finnish Broca's aphasics. The speech problems of our patients seemed to indicate higher level motor encoding problems of linguistic information rather than peripheral articulatory deficits.

Vertical hyoid bone displacement and fundamental frequency of phonation.

Vertical displacement of the hyoid bone as well as its effects on F0 were studied using five excised human larynges. Cranial force introduced to the hyoid bone caused a widening of the vestibule of the larynx, enlargement of the laryngeal ventricles, abduction of the ventricular folds, heightening of the epiglottis and slight abduction of the vocal folds. The displacement (X +/- SD) of the anterior part (corpus) of the bone was 8.0 +/- 5.2 mm and of the posterior part, 22.2 +/- 6.1 mm with a 10 N force. The difference was statistically significant and was found to depend mainly on the tight middle hyothyroid ligament. The cranial force displacing the hyoid bone invariably showed a positive relationship with F0. The F0 changes were statistically significant but relatively small (X +/- SD): 8 +/- 8.4 Hz (about 10%) with an intact hyothyroid ligament. When the subglottal pressure was low, a change in the vibratory pattern of the vocal folds was found in several specimens. The F0 changes found in the present study are too small to explain alone the differences in the so-called intrinsic F0 of vowels. However, they are believed to contribute to this phenomenon.

Observations on the structure and the biomechanics of the cricothyroid articulation.

We examined quantitatively the ventrodorsal gliding occurring along a sagittal plane in the cricothyroid articulation. For this purpose we used 10 fresh excised human larynges taken at autopsy. Furthermore we examined the morphology, the hydroxyproline content and collagen types of the ligaments and the articular capsule of the cricothyroid articulation. This articulation appeared to be a synovial joint, supported by two ligaments: the lateral and posterior ceratocricoid ligament and articular capsule. The ligaments and the capsule contained both type I and type III collagen fibres and they were rich in elastin fibres 1-2.5 microns in diameter. Ventrodorsal gliding was generally possible when the joint was not rotated to its extremes. The marked individual variation was not essentially affected by sex or age. The collagen content of the lateral ceratocricoid ligament showed a statistically significant negative correlation with the gliding. The articular facet of the cricoid cartilage, which was not usually well-shaped, limits the gliding. A force of +/- 1.0 N caused on the average a change of +/- 1.0 mm in the length of the vocal cord. Further research is needed to evaluate the physiological importance of these findings.

Speech articulation after subtotal glossectomy and reconstruction with a myocutaneous flap.

Speech samples of 9 subjects (8 males, 1 female) were recorded before and 0.5-2 years after a partial glossectomy and reconstruction with a pectoralis major myocutaneous flap. A reading sample, a list of meaningful and nonsense words, and a list of sustained vowels were recorded. The speech samples were evaluated by pairs of naive listeners and using acoustic analysis of the vowel production. Each pair listened to the recordings of only one patient. Inter-rater agreement was satisfactory. The general impression of the speech outcome varied from normal to moderately impaired. The perceptually estimated impairments of speech articulation in the after/before comparisons were statistically significant. Only the first formant of the vowel /i/ (rise) and the second formant of the vowel /a/ (drop) changed significantly at the group level. There was a negative correlation (r = -0.79) between the extent of tongue resection and the drop of the second formant of the vowel /a/. The perceptual variables showed a relationship (r = 0.74-0.82) with the changes in the level of the second formant of the vowel /i/. The relationship that emerged between the perceptual estimates and the objective acoustic parameters suggests that it will be possible to develop clinically relevant test batteries for articulatory quality analysis.

Parameterization of the voice source by combining spectral decay and amplitude features of the glottal flow.

A new method is presented for the parameterization of glottal volume velocity waveforms that have been estimated by inverse filtering acoustic speech pressure signals. The new technique, Parameter for Spectral and Amplitude Features of the Glottal Flow (PSA), combines two features of voice production, the AC value and the spectral decay of the glottal flow, both of which contribute to changes in vocal loudness. PSA yields a single parameter that characterizes the glottal flow in different loudness conditions. By analyzing voices of 8 speakers it was shown that the new parameter correlates strongly with the sound pressure level of speech.

Relationship between subjective voice complaints and acoustic parameters in female teachers' voices.

The aim of the study was to identify the acoustic correlates of female teachers' subjective voice complaints by recording their voices in their working environment. The subjects made recordings during lessons (N = 10) and breaks (N = 11). The subjects were divided into 2 groups: those with few voice complaints (FC group) and those with many voice complaints (MC group). The speech sample made in the breaks was maximally sustained /a/, from which fundamental frequency (F0), jitter, and shimmer were analyzed. The classroom samples were analyzed for F0, sound pressure level (SPL), and F0 time (the active vibration time of the vocal folds). Additionally, an index for assessing voice loading is presented. The results revealed a tendency of the MC group to have higher F0 and lower SPL and perturbation values than the FC group. The index values correlated moderately with the subjective vocal complaints.

External laryngeal frame function in voice production revisited: a review.

Research indicates significant contribution of extrinsic laryngeal mechanisms to voice production. This article reviews the major theories of the role of the external laryngeal factors in voice production and relevant experimental data. The review suggests that partly neglected external factors and possibly even misinterpretation of some of the recently documented individual variation in physiological data may have unnecessarily complicated the issues pertaining to the interplay between the physiological mechanisms of the larynx. The implications of contemporary findings and documentation in the modeling of the extrinsic factors are discussed and a synthesis of empirical data into two simple models of the extrinsic forces of pitch control is presented. Also suggested by the review, a basic principle, probably underlying the laryngeal control of phonation, is put forward.

Vocal-fold collision mass as a differentiator between registers in the low-pitch range.

Register shift between the chest and falsetto register is generally studied in the higher-than-speaking pitch range. However, a similar difference can also be produced at speaking pitch level. The shift from breathy "falsetto" phonation to normal chest voice phonation was studied in normal female (pitch range 170-180 Hz) and male (pitch range 94-110 Hz) subjects. The phonations gliding from falsetto to normal chest voice were analyzed using iterative adaptive inverse filtering and electroglottography. Both trained and untrained, as well as female and male subjects, were able to produce an abrupt register shift from soft falsetto to soft chest register phonation. The differences between male and female speakers in the glottal flow waveforms were smaller than expected. The register shift is interpreted in terms of a "critical mass" concept of chest register phonation.

A physiological and acoustic study on voiced bilabial fricative/beta:/as a vocal exercise.

The voiced bilabial fricative/beta:/has been used as a vocal exercise. The present study investigated the effects of the exercise on voice production and voice source. This study compared vowel phonation on the syllable /a:p/ with the production of the exercise and vowel phonation before and immediately after the exercise. The methods were (a) dual-channel electroglottography, from which the vertical laryngeal position was derived, (b) electromyography using surface electrodes, and (c) inverse filtering of the acoustic signal to obtain an estimate of the voice source. In the production of /beta:/ as compared with vowel phonation in most of the cases, the vertical laryngeal position seemed to be higher, the muscular activity of the larynx lower, and the slope of the voice source spectrum steeper. In vowel phonation after the exercise, the muscular activity seemed to be lower in most cases, although the voice source remained unchanged. This seems to indicate improved vocal economy.

Effects of prolonged oral reading on F0, SPL, subglottal pressure and amplitude characteristics of glottal flow waveforms.

The effects of prolonged (5x45 minute) reading (vocal loading) on fundamental frequency (F0), sound pressure level (SPL), subglottal (intraroral) pressure (p), and two glottal flow waveform parameters (AC amplitude of glottal flow, f, and negative peak amplitude of differentiated flow (d) of normal female and male subjects (N = 80) were studied. Two rest (morning and noon) and three loading (two in the morning and one in the afternoon) samples were recorded and analyzed. The glottal waveforms were obtained by inverse filtering of the acoustic pressure waveforms of speaking voice samples. The analyses were based on measurement and inverse filtering of the first stressed syllable of "paappa" words repeated 3x5 times for normal, as soft as possible, and as loud as possible phonation. In normal phonation the parameter values changed statistically significantly due to loading. In many cases the values obtained in the morning samples changed after the first loading session. This is interpreted as a vocal "warming-up effect." Especially in soft phonation p, d, and f were sensitive indicators of vocal loading. In both normal and soft phonation, the SPL, p, d, and f values tended to rise due to prolonged reading in the morning and afternoon samples, indicating increased effort (normal phonation) and a rise in the phonatory threshold (soft phonation). The lunch break vocal rest ("rest effect") considerably affected the parameter values in many cases.

Simultaneous videofluorographic and dual-channel electroglottographic registration of the vertical laryngeal position in various phonatory tasks.

Simultaneous tracking of the vertical laryngeal position in various phonatory tasks was performed for 2 subjects (one male, one female) using dual-channel electroglottography (EGG) and videofluorography (videofluoroscopy). The tasks included phonation on [a:] with voluntary repeated (1) heightening and (2) lowering of the laryngeal position; alternation between [a:] and phonation on (3) [b], (4) [m], and (5) the voiced bilabial fricative [beta:]; and (6) production of the corner vowels [a, i, u]. EGG and videofluorography agreed about the direction of changes in the vertical laryngeal position in most cases. Most disagreements were found in the amount of changes. Reasons for the discrepancies, including, for example, changes in the resting position of the larynx and anteroposterior movements of the cartilages, are discussed. It can be concluded that dual-channel EGG is a valuable clinical and pedagogical tool for the analysis of the vertical displacement of larynx in well-specified phonatory tasks. The method should act most reliably on separately phonated vowels. Its applicability for studying laryngeal biomechanics more wholistically, however, is limited.

Occupational risk factors and voice disorders.

From the point of view of occupational health, the field of voice disorders is very poorly developed as compared, for instance, to the prevention and diagnostics of occupational hearing disorders. In fact, voice disorders have not even been recognized in the field of occupational medicine. Hence, it is obviously very rare in most countries that the voice disorder of a professional voice user, e.g. a teacher, a singer or an actor, is accepted as an occupational disease by insurance companies. However, occupational voice problems do not lack significance from the point of view of the patient. We also know from questionnaires and clinical studies that voice complaints are very common. Another example of job-related health problems, which has proved more successful in terms of its occupational health status, is the repetition strain injury of the elbow, i.e. the "tennis elbow". Its textbook definition could be used as such to describe an occupational voice disorder ("dysphonia professional is"). In the present paper the effects of such risk factors as vocal loading itself, background noise and room acoustics and low relative humidity of the air are discussed. Due to individual factors underlying the development of professional voice disorders, recommendations rather than regulations are called for. There are many simple and even relatively low-cost methods available for the prevention of vocal problems as well as for supporting rehabilitation.

Effects of sound amplification on teachers' speech while teaching.

Voice problems are common among teachers. This is most likely due to the heavy vocal load of their profession. The present study investigated one possible method to decrease the vocal load. The effects of amplification on classroom speech were studied on five Icelandic teachers (three females, two males, mean age 51 years). Classroom speech was recorded with a portable DAT recorder and a head-mounted microphone, first under ordinary conditions and in the next week while using electrical sound amplification. The average fundamental frequency (F0), sound pressure level (SPL) and phonation time were measured. According to the results, amplification significantly lowered both F0 (average 8.6 Hz for the females and 11.3 Hz for the males, p = 0.002 and 0.0001, respectively) and SPL (about 1 dB for both genders, p < 0.05), while phonation time was not significantly affected. The results suggest that electric amplification is likely to reduce vocal load.

Effects of amplified and damped auditory feedback on vocal characteristics.

This study tested two possible methods for reducing vocal load e.g. during classroom speech. Six female subjects read aloud from a text (1) under normal circumstances, (2) while hearing their own voice amplified (through headphones) and (3) with auditory feedback damped by foam plastic earplugs inserted in the outer ear canal. Fundamental frequency (F0) and sound pressure level (SPL) decreased during both amplified and damped feedback. Additionally, during amplification the relative level of F0 compared to that of the first formant diminished, likewise the alpha ratio. These changes may indicate reduced vocal fold adduction. The results suggest that both amplification and damping of auditory feedback may reduce vocal load during phonation.