Irma Ilomäki

Effects of voice training and voice hygiene education on acoustic and perceptual speech parameters and self-reported vocal well-being in female teachers

Voice education programs may help in optimizing teachers’ voice use. This study compared effects of voice training (VT) and voice hygiene lecture (VHL) in 60 randomly assigned female teachers. All 60 attended the lecture, and 30 completed a short training course in addition. Text reading was recorded in working environments and analyzed for fundamental frequency (F0), equivalent sound level (Leq), alpha ratio, jitter, shimmer, and perceptual quality. Self-reports of vocal well-being were registered. In the VHL group, increased F0 and difficulty of phonation and in the VT group decreased perturbation, increased alpha ratio, easier phonation, and improved perceptual and self-reported voice quality were found. Both groups equally self-reported increase of voice care knowledge. Results seem to indicate improved vocal well-being after training.

Vocal symptoms among teachers with and without voice education

This study investigates the amount of voice training received by teachers in Finland and compares the incidence of vocal symptoms among teachers with shorter, longer or no vocal education. Participating were 124 primary, secondary and upper secondary school teachers; 63% of the teachers had received no vocal training, 15% had received short-term and 22% longer-term training. The incidence of symptoms was lowest in teachers with long-term training and highest in teachers with short-term training. The differences were non-significant among all teachers and females, but significant among males. Speech training seems to protect male teachers from vocal problems better than female teachers. Short-term training may lead to increased awareness of vocal symptoms, which can be helpful in voice protection.

Assessment of vocal capacity of Finnish university students.

This article summarizes the results for a total of 189 female and 63 male university students (mean age 23 and 26 years, respectively) from the following vocal capacity tests: measurement of (1) vital capacity, (2) average airflow in phonation (on [o:]), (3) maximum duration of sustained blowing, (4) maximum phonation time (on [o:, z:]), (5) maximum duration of [s:], (6) the ratio of the duration of [s:] to [z:] (s/z ratio), (7) phonation quotient (the ratio between vital capacity and maximum phonation time), (8) the lowest possible tone, (9) mean fundamental frequency (F0) in normal and loud text reading and in shouting, (10) difference between the lowest tone and mean F0 in text reading and in shouting, (11) F0 range in text reading, (12) equivalent sound level of normal and loud reading and of shouting in maximum loudness, (13) phonetogram (voice range profile) and (14) long-term average spectrum of text reading. Voice quality is also evaluated perceptually, and additionally, data on subjects’ self-reported vocal fatigue symptoms in general or after a vocally loading task were collected. The value of these measurements from the point of view of assessment of vocal capacity will be discussed.

Self-evaluation of voice as a treatment outcome measure.

This study addressed two self-evaluation questionnaires in investigating the effects of voice hygiene lecture (VHL, 3 h) and additional voice training (VT) or Voice Massage™ (VM; both 5 h) in 90 female teachers. The subjects assessed their voice quality, ease of phonation and tiredness of throat before and after a working day at the beginning and end of the school term using a visual analogue scale (VAS) (Questionnaire 1). At the end of the term, the degree of positive influence of the interventions was reported on VAS, and the type of influence was indicated by choosing one or more of three alternatives (voice quality, audibility and endurance) or by writing a free comment (Questionnaire 2). Questionnaire 1 was pretested and found to be reliable and valid for self-evaluation of voice. At the end of term, the VM and VT groups reported more positive influence of the interventions than did the VHL group. The reported influence did not correlate with working-day-related changes in sensations. Increased difficulty of phonation and tiredness of throat was found in the VHL group at the end of the term. However, the groups did not differ significantly from each other. The challenges of self-evaluations as outcome measures are discussed.

A comparison of the effects of Voice Massage and voice hygiene lecture on self-reported vocal well-being and acoustic and perceptual speech parameters in female teachers.

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 α-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.

One-year follow-up study of self-evaluated effects of Voice Massage™, voice training, and voice hygiene lecture in female teachers

Abstract This study collected data on self-reported symptoms of vocal fatigue among Finnish female primary school teachers (n = 90) before and 6 months and 12 months after three types of interventions that aimed at improving vocal well-being at work. All subjects were given a voice hygiene lecture (3 hours), and, additionally, a randomly chosen group of 30 subjects was given voice massage treatment and another group voice training (5 × 1 hour sessions) over 2 months. The subjects answered a questionnaire over the Internet concerning symptoms of vocal fatigue. The sum score of symptoms decreased significantly in all three groups through the period of investigation. All three interventions improved the teachers’ vocal well-being over the long term.

Electroglottographic contact quotient in different phonation types using different amplitude threshold levels

Contact quotient (CQ), measured by electroglottogram (EGG), is a ratio which illustrates the duration of vocal fold contact during one vocal fold period. In the present study CQEGG was calculated from a sustained vowel phonation in three different phonation types (breathy, normal, pressed) at three amplitude threshold levels (25%, 35%, 50%). CQEGG values were compared with experts’ perceptual evaluation of the firmness of phonation. The contact time of the vocal folds differed significantly between the different phonation types at all threshold levels (P < 0.01). Perceptual evaluation correlated best with CQEGG at threshold levels 25% and 35%. The results of the linear regression model suggested that by using threshold level 25% the effect of F0 and SPL on CQEGG were not significant.

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.

Vocal Fatigue Symptoms and Laryngeal Status in Relation to Vocal Activity Limitation and Participation Restriction

OBJECTIVES The study aims to investigate the vocal fatigue symptoms and laryngeal status in relation to vocal activity limitations and vocal participation restrictions. STUDY DESIGN This is a case-control study. METHODS Two hundred six teachers were divided into two groups based on the frequency of their self-reported vocal symptoms being more or less than the mean of reported frequency. The study compared odds for activity limitation and participation restriction in relation to frequency of vocal symptoms, number of vocal symptoms recurring weekly, and organic laryngeal changes. Activity limitation and participation restriction were studied using the Voice Activity and Participation Profile questionnaire. RESULTS Increased odds were found for teachers with frequent vocal symptoms and especially those with one or more vocal symptom recurring weekly. Odds were found to be 2.6-8.5 times more likely in teachers with more frequent vocal symptoms. The odds increased dramatically with increase of the number of vocal symptoms recurring weekly. Laryngeal organic changes were found to increase the odds but insignificantly. CONCLUSIONS Teachers with frequent vocal symptoms, especially those with vocal symptoms recurring weekly, have increased odds ratio for vocal activity limitation and vocal participation restrictions. High scores or frequent occurrence of self-reported vocal fatigue symptoms must be taken seriously in the evaluation of vocal working ability.

Cepstral and Perceptual Investigations in Female Teachers With Functionally Healthy Voice

PURPOSE The present study aimed at measuring the smoothed and non-smoothed cepstral peak prominence (CPPS and CPP) in teachers who considered themselves to have normal voice but some of them had laryngeal pathology. The changes of CPP, CPPS, sound pressure level (SPL) and perceptual ratings with different voice tasks were investigated and the influence of vocal pathology on these measures was studied. METHOD Eighty-four Finnish female primary school teachers volunteered as participants. Laryngoscopically, 52.4% of these had laryngeal changes (39.3% mild, 13.1% disordered). Sound recordings were made for phonations of comfortable sustained vowel, comfortable speech, and speech produced at increased loudness level as used during teaching. CPP, CPPS and SPL values were extracted using Praat software for all three voice samples. Sound samples were also perceptually evaluated by five voice experts for overall voice quality (10 point scale from poor to excellent) and vocal firmness (10 point scale from breathy to pressed, with normal in the middle). RESULTS The CPP, CPPS and SPL values were significantly higher for vowels than for comfortable speech and for loud speech compared to comfortable speech (P < 0.001). Significant correlations were found between SPL and cepstral measures. The loud speech was perceived to be firmer and have a better voice quality than comfortable speech. No significant relationships of the laryngeal pathology status with cepstral values, perceptual ratings, or voice SPLs were found (P > 0.05). CONCLUSION Neither the acoustic measures (CPP, CPPS, and SPL) nor the perceptual evaluations could clearly distinguish teachers with laryngeal changes from laryngeally healthy teachers. Considering no vocal complaints of the subjects, the data could be considered representative of teachers with functionally healthy voice.