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.

Electroglottogram-based estimation of vocal economy: 'quasi-output-cost ratio'.

Impact stress (IS) has been regarded as the main loading factor in voice production. To quantify the cost of voice production, an output-cost ratio (OCR) was proposed, which concerns acoustic output (pressure P) in relation to IS: OCR = 20 log P(sup)/P(0) - 20 log IS/IS(0) [1,2]. IS is difficult to measure directly in humans. However, it has been found to correlate with closed quotient (CQ, closed time/period length) measured by electroglottogram (CQ(EGG)) [3]. The present study proposes a noninvasive estimate of OCR, the quasi-output-cost ratio (QOCR): (sound pressure level (SPL)/CQ(EGG)) x (period length (T)/T(0)). T(0) is set at 0.005 for females and 0.01 for males, corresponding to the respective period lengths of the mean F(0) in female and male speech (i.e. 200 and 100 Hz). QOCR was tested for 62 healthy females (23 teachers, 18 university students with voice training and 21 without). The teachers had a higher QOCR than the students in loud speech, but QOCR did not correlate with symptoms of vocal fatigue after a vocal loading test. QOCR seems to be a promising tool to quantify vocal loading but naturally not vocal loadedness.

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 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.

Acoustic measures and self-reports of vocal fatigue by female teachers.

This study investigated the relation of symptoms of vocal fatigue to acoustic variables reflecting type of voice production and the effects of vocal loading. Seventy-nine female primary school teachers volunteered as subjects. Before and after a working day, (1) a 1-minute text reading sample was recorded at habitual loudness and loudly (as in large classroom), (2) a prolonged phonation on [a:] was recorded at habitual speaking pitch and loudness, and (3) a questionnaire about voice quality, ease, or difficulty of phonation and tiredness of throat was completed. The samples were analyzed for average fundamental frequency (F0), sound pressure level (SPL), and phonation type reflecting alpha ratio (SPL [1-5 kHz]-SPL [50 Hz-1 kHz]). The vowel samples were additionally analyzed for perturbation (jitter and shimmer). After a working day, F0, SPL, and alpha ratio were higher, jitter and shimmer values were lower, and more tiredness of throat was reported. The average levels of the acoustic parameters did not correlate with the symptoms. Increase in jitter and mean F0 in loud reading correlated with tiredness of throat. The results seem to suggest that, at least among experienced vocal professionals, voice production type had little relevance from the point of view of vocal fatigue reported. Differences in the acoustic parameters after a vocally loading working day mainly seem to reflect increased muscle activity as a consequence of vocal loading.

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.

One-year follow-up study of self-evaluated effects of voice massage, voice training, and voice hygiene lecture in female teachers.

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 x 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.

Relationships between self-evaluations of voice and working conditions, background factors, and phoniatric findings in female teachers.

Self-evaluations of voice, working conditions, and results of phoniatric examination were studied in 78 female primary school teachers. Most teachers evaluated their vocal capabilities as 'normal'; nevertheless 1/3 reported two or more weekly symptoms. Unsatisfactory air quality, background noise, and stressful working conditions were seen as the most harmful environmental factors. A total of 14% of the subjects had organic laryngeal changes, 37% had mild changes, and 49% were found to be healthy. These findings did not correlate with self-evaluation of voice, vocal symptoms, or voice-related quality of life. Teaching experience or teaching hours per week did not correlate with laryngeal findings or symptoms. The results illustrate the complex nature of voice assessment and the need of assessment tools specially suited for functionally healthy voice professionals.

Immediate effects of 'voice massage' treatment on the speaking voice of healthy subjects.

'Voice massage' (VM) treatment includes manipulation of muscles related to speech production and voice and breathing exercises. This study investigated the effects of VM in 10 healthy subjects (5 females, 5 males). They recorded repetitions of the word 'paappa' at normal loudness and as softly as possible and read a text sample before and after 1-hour (1) VM treatment, (2) fast walking, (3) sitting in a library and (4) lying on a bed. Subglottic pressure was estimated from oral pressure during [p]. Transglottal flow and glottal resistance were measured. Voice production was studied with electroglottography. Fundamental frequency, sound pressure level (SPL) and alpha ratio [(SPL of the range 1-5 kHz) - (SPL of the range 50 Hz-1 kHz)] were calculated from text samples, which were also evaluated by 7 voice experts. A questionnaire was used to record subjects' sensations. Changes after lying and sitting suggest lowered effort in phonatory muscles, while after fast walking effort seemed to increase. After VM no significant changes were observed in voice parameters or perceptual quality, but ease of phonation and reduced tension in the neck, shoulders and back were reported. The effects of VM may be partly psychological, partly related to a search of phonatory balance.