Voice problems are common among teachers. This is most likely due to the heavy vocal load of thei... more 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.
... It has been estimated on the basis of the classroom noise levels that the teacher's spee... more ... It has been estimated on the basis of the classroom noise levels that the teacher's speech output varies ... Vilkman E. Occupational risk factors and voice disor-ders. ... E, Sihvo M. Loading changes in time-based parameters of glottal flow waveforms in different ergonomic conditions. ...
The study presents experimental investigations of non-linear vibration effects, particularly bifu... more The study presents experimental investigations of non-linear vibration effects, particularly bifurcation phenomena in the vibrations of human vocal folds. The vocal fold vibrations were excited by airflow and the microphone, the pressure transducers, an electroglottograph and the laser vibrometer registered the phonation and vibration of the vocal folds. Furthermore the vocal fold oscillations were observed optically by strobovideoscopy and videokymography. Bifurcations in the vocal fold vibrations were observed when smoothly changing the tension of the vocal folds.
The contribution presents information on the experimental investigation of the glottal sound sour... more The contribution presents information on the experimental investigation of the glottal sound source with excised human larynges. The vocal fold vibrations were excited by airflow and monitored acoustically, electroglottographically as well as by means of laser vibrometry, pressure transducers, videokymography and stroboscopy techniques. The paper is focused on 1) presenting a method for monitoring non-linear vibration effects, when bifurcations appear during phonation by changing the tension of the vocal folds, and 2) on development of a method for casting laryngeal cavities using plaster and metal materials for determining the vocal fold shape in a defined phonation position.
Objective: The aim of this study was to analyse the associations between the spirometry parameter... more Objective: The aim of this study was to analyse the associations between the spirometry parameter changes in relation to laryngeal finding changes and self-reported voice and throat symptom changes among patients undergoing a histamine challenge test. Patients and Methods: Thirty adult patients with a chronic cough underwent a histamine challenge test. Videolaryngostroboscopy and voice and throat symptoms were assessed using a visual analogue scale immediately before and after the challenge test. Correlations between the relative changes in spirometry values in relation to the change in vocal fold oedema and redness and self-reported voice and throat symptom changes during the challenge test were assessed. Results: A correlation between the relative change in inspiratory and expiratory air flow values and the change in voice and throat symptoms during the histamine challenge test was found. The vocal fold oedema, visible on videolaryngostroboscopy, caused by the histamine challenge ...
This study tested two possible methods for reducing vocal load e.g. during classroom speech. Six ... more 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.
We examined quantitatively the ventrodorsal gliding occurring along a sagittal plane in the crico... more 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.
Vocal loading-related subjective symptoms were studied in a day-long vocal loading test. The voic... more Vocal loading-related subjective symptoms were studied in a day-long vocal loading test. The voices of 40 female and 40 male voluntary young students were loaded by having them read aloud a novel for five times 45 min. The subjective symptoms that occurred during the vocal loading session were reported by filling in a questionnaire after each session. The responses loaded on five factors in a factor analysis: (1) 'central fatigue'; (2) 'symptoms of the neck, shoulders and back'; (3) 'drying in the mouth and throat'; (4) 'symptoms of the throat'; (5) 'symptoms of the voice'. The exposure groups (5 females and 5 males per cell) consisted of eight combinations of the following factors: (1) low (25 +/- 5%) or high (65 +/- 5%) relative humidity of ambient air; (2) low [<65 dB(SPL)] or high [>65 dB(SPL)] speech output level of vocal loading; (3) sitting or standing posture during vocal loading. The lowest mean score for symptoms pooled over the test were found in 'symptoms of the neck, shoulders and back' and the highest mean symptom score in 'drying in the mouth and throat' and 'symptoms of the throat'. Most symptoms were at their minimum during the first loading session and increased statistically significantly to a peak mean value after three or five vocal loading sessions. Statistically significant differences in the mean level between the gender or exposure groups emerged for 'central fatigue' (humidity had clear effects) and 'symptoms of the neck, shoulders and back' (gender, humidity and posture had clear effects). In these cases, females had more symptoms than males; the low-humidity group had more symptoms than the high-humidity group, and the standing subjects had more symptoms than the sitting subjects.
ABSTRACT This study compared the effects of Voice Massage (VM) and a voice hygiene lecture (VHL) ... more ABSTRACT This study compared the effects of Voice Massage (VM) and a voice hygiene lecture (VHL) on 60 female teachers. VM is a Finnish massage method which treats muscles related to voice production. All subjects attended the VHL (3 h). Half of them were randomly assigned to the VM group, the other half received only VHL. VM was given 5 times in 1-hour sessions at intervals of 1-2 weeks. At the beginning and end of the autumn school term, before and after a working day, (1) a 1-min reading sample was recorded at both the subject's habitual loudness and loudly, (2) a prolonged phonation on [a:] was recorded at habitual speaking pitch and (3) a questionnaire on voice quality, ease or difficulty of phonation, and tiredness of the throat was completed. The reading samples were analysed for the fundamental frequency (F0), equivalent sound level (Leq) and alpha-ratio [Leq (1-5 kHz)-Leq (50-1,000 Hz)]. The vowel samples were analysed for the F0 and Leq, as well as for jitter and shimmer. The reading samples were also evaluated perceptually by 3 speech trainers. The mean F0 and difficulty of phonation increased from the beginning to the end of the term in the VHL group (p = 0.026, p = 0.007, respectively). In the VM group, the perceived firmness of loud reading decreased (p = 0.026). The results suggest that VM may help in sustaining vocal well-being during a school term.
Voice problems are common among teachers. This is most likely due to the heavy vocal load of thei... more 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.
... It has been estimated on the basis of the classroom noise levels that the teacher's spee... more ... It has been estimated on the basis of the classroom noise levels that the teacher's speech output varies ... Vilkman E. Occupational risk factors and voice disor-ders. ... E, Sihvo M. Loading changes in time-based parameters of glottal flow waveforms in different ergonomic conditions. ...
The study presents experimental investigations of non-linear vibration effects, particularly bifu... more The study presents experimental investigations of non-linear vibration effects, particularly bifurcation phenomena in the vibrations of human vocal folds. The vocal fold vibrations were excited by airflow and the microphone, the pressure transducers, an electroglottograph and the laser vibrometer registered the phonation and vibration of the vocal folds. Furthermore the vocal fold oscillations were observed optically by strobovideoscopy and videokymography. Bifurcations in the vocal fold vibrations were observed when smoothly changing the tension of the vocal folds.
The contribution presents information on the experimental investigation of the glottal sound sour... more The contribution presents information on the experimental investigation of the glottal sound source with excised human larynges. The vocal fold vibrations were excited by airflow and monitored acoustically, electroglottographically as well as by means of laser vibrometry, pressure transducers, videokymography and stroboscopy techniques. The paper is focused on 1) presenting a method for monitoring non-linear vibration effects, when bifurcations appear during phonation by changing the tension of the vocal folds, and 2) on development of a method for casting laryngeal cavities using plaster and metal materials for determining the vocal fold shape in a defined phonation position.
Objective: The aim of this study was to analyse the associations between the spirometry parameter... more Objective: The aim of this study was to analyse the associations between the spirometry parameter changes in relation to laryngeal finding changes and self-reported voice and throat symptom changes among patients undergoing a histamine challenge test. Patients and Methods: Thirty adult patients with a chronic cough underwent a histamine challenge test. Videolaryngostroboscopy and voice and throat symptoms were assessed using a visual analogue scale immediately before and after the challenge test. Correlations between the relative changes in spirometry values in relation to the change in vocal fold oedema and redness and self-reported voice and throat symptom changes during the challenge test were assessed. Results: A correlation between the relative change in inspiratory and expiratory air flow values and the change in voice and throat symptoms during the histamine challenge test was found. The vocal fold oedema, visible on videolaryngostroboscopy, caused by the histamine challenge ...
This study tested two possible methods for reducing vocal load e.g. during classroom speech. Six ... more 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.
We examined quantitatively the ventrodorsal gliding occurring along a sagittal plane in the crico... more 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.
Vocal loading-related subjective symptoms were studied in a day-long vocal loading test. The voic... more Vocal loading-related subjective symptoms were studied in a day-long vocal loading test. The voices of 40 female and 40 male voluntary young students were loaded by having them read aloud a novel for five times 45 min. The subjective symptoms that occurred during the vocal loading session were reported by filling in a questionnaire after each session. The responses loaded on five factors in a factor analysis: (1) 'central fatigue'; (2) 'symptoms of the neck, shoulders and back'; (3) 'drying in the mouth and throat'; (4) 'symptoms of the throat'; (5) 'symptoms of the voice'. The exposure groups (5 females and 5 males per cell) consisted of eight combinations of the following factors: (1) low (25 +/- 5%) or high (65 +/- 5%) relative humidity of ambient air; (2) low [<65 dB(SPL)] or high [>65 dB(SPL)] speech output level of vocal loading; (3) sitting or standing posture during vocal loading. The lowest mean score for symptoms pooled over the test were found in 'symptoms of the neck, shoulders and back' and the highest mean symptom score in 'drying in the mouth and throat' and 'symptoms of the throat'. Most symptoms were at their minimum during the first loading session and increased statistically significantly to a peak mean value after three or five vocal loading sessions. Statistically significant differences in the mean level between the gender or exposure groups emerged for 'central fatigue' (humidity had clear effects) and 'symptoms of the neck, shoulders and back' (gender, humidity and posture had clear effects). In these cases, females had more symptoms than males; the low-humidity group had more symptoms than the high-humidity group, and the standing subjects had more symptoms than the sitting subjects.
ABSTRACT This study compared the effects of Voice Massage (VM) and a voice hygiene lecture (VHL) ... more ABSTRACT This study compared the effects of Voice Massage (VM) and a voice hygiene lecture (VHL) on 60 female teachers. VM is a Finnish massage method which treats muscles related to voice production. All subjects attended the VHL (3 h). Half of them were randomly assigned to the VM group, the other half received only VHL. VM was given 5 times in 1-hour sessions at intervals of 1-2 weeks. At the beginning and end of the autumn school term, before and after a working day, (1) a 1-min reading sample was recorded at both the subject's habitual loudness and loudly, (2) a prolonged phonation on [a:] was recorded at habitual speaking pitch and (3) a questionnaire on voice quality, ease or difficulty of phonation, and tiredness of the throat was completed. The reading samples were analysed for the fundamental frequency (F0), equivalent sound level (Leq) and alpha-ratio [Leq (1-5 kHz)-Leq (50-1,000 Hz)]. The vowel samples were analysed for the F0 and Leq, as well as for jitter and shimmer. The reading samples were also evaluated perceptually by 3 speech trainers. The mean F0 and difficulty of phonation increased from the beginning to the end of the term in the VHL group (p = 0.026, p = 0.007, respectively). In the VM group, the perceived firmness of loud reading decreased (p = 0.026). The results suggest that VM may help in sustaining vocal well-being during a school term.
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