Differences in Self-Rated, Perceived, and Acoustic Voice Qualities Between High- and Low-Fatigue Groups

Objectives

The present study was performed to examine which factors among self-rated scales, perceptual evaluations, and acoustic parameters, calculated from sustained vowels, are reliable indicators of physical and mental fatigues.

Methods

A total of 73 volunteers (male:female, 52:21), aged 19–24 years, were enrolled in this study. We defined the high- and low-fatigue groups using the Chalder Fatigue Scale score. For assessment of self-rated symptoms, each subject was asked to complete Voice Handicap Index (VHI) and Voice Rating Scale (VRS). For perceptual evaluations, three clinicians assessed each subject’s vocal quality on the Grade, Roughness, Breathiness, Asthenia, Strain Scale. For acoustic analysis, each subject was asked to produce sustained vowels /a/, /e/, /i/, /o/, and /u/ for 3 seconds. Then, the habitual fundamental frequency (F₀), jitter, shimmer, F₀ tremor, mean F₀, standard deviation of F₀, maximum F₀, minimum F₀, normalized noise energy, harmonic-to-noise ratio (HNR), signal-to-noise ratio (SNR), amplitude tremor, and ratio within 2–4 kHz were calculated using Dr. Speech software.

Results

In men, VHI, VRS, F₀ tremor, shimmer, HNR, SNR, and amplitude tremor were related to mental fatigue. In women, only VHI was related to physical fatigue, and none of the acoustic parameters was related to the fatigue score. Perceptual evaluations were not related to fatigue in men or women.

Conclusions

These findings suggest that self-rated symptoms and acoustic parameters related to voice quality are indicative of mental fatigue, and these features are prominent in men.     

Spectral- and Cepstral-Based Measures During Continuous Speech: Capacity to Distinguish Dysphonia and Consistency Within a Speaker

Spectral- and cepstral-based acoustic measures are preferable to time-based measures for accurately representing dysphonic voices during continuous speech. Although these measures show promising relationships to perceptual voice quality ratings, less is known regarding their ability to differentiate normal from dysphonic voice during continuous speech and the consistency of these measures across multiple utterances by the same speaker. The purpose of this study was to determine whether spectral moments of the long-term average spectrum (LTAS) (spectral mean, standard deviation, skewness, and kurtosis) and cepstral peak prominence measures were significantly different for speakers with and without voice disorders when assessed during continuous speech. The consistency of these measures within a speaker across utterances was also addressed. Continuous speech samples from 27 subjects without voice disorders and 27 subjects with mixed voice disorders were acoustically analyzed. In addition, voice samples were perceptually rated for overall severity. Acoustic analyses were performed on three continuous speech stimuli from a reading passage: two full sentences and one constituent phrase. Significant between-group differences were found for both cepstral measures and three LTAS measures (P < 0.001): spectral mean, skewness, and kurtosis. These five measures also showed moderate to strong correlations to overall voice severity. Furthermore, high degrees of within-speaker consistency (correlation coefficients ≥0.89) across utterances with varying length and phonemic content were evidenced for both subject groups.     

Voice Training and Changing Weight—Are They Reflected in Speaking Fundamental Frequency, Voice Range, and Pitch Breaks of 13-Year-Old Girls? A Longitudinal Study

Objective

Assessment of the voice-change progress of 20 girls (12–13 years) over 1 year by observing changes in speaking fundamental frequency (SFo), voice range, and register pitch breaks in the context of weight, height, voice training, and self-perception.

Study Design

One-year longitudinal collective case study.

Method

Twenty girls were recorded at the beginning and end of a year; nine girls were recorded another three times. SFo, vocal range, and characteristics were analyzed and interactions between these data assessed against weight and height to indicate pubertal development, and to test the hypothesis that changes in weight, height, SFo, and pitch breaks were related. Effects of training and the girls' self-perception of their voice use were also assessed.

Results

Vocal characteristics changed as the girls passed through different weight ranges. During 47.5–52.4 kg (called band 2) and 52.4–57.5 kg (band 3), there was progressive contraction of vocal range and in some girls a slight rise in SFo between recording times 1 and 5. Both high- and low-pitch breaks were present in 45% of girls' voices. Girls in band 4 (<57.5 kg) had an increased vocal range, and pitch breaks in vocal-range areas that indicated the development of adult vocal registers. In this study, voice-trained girls were heavier, had higher SFo, used wider speech-range inflection, had a higher vocal range, and greater voice-use confidence; all girls lost confidence in their voice use over the year.

Conclusions

In this longitudinal study of twenty 13-year-old girls, voice changes in SFo, vocal range, and pitch-break frequency were synchronous with certain weight ranges. Girls with training registered higher maximum phonational frequency and were more confident in their voice use than girls without training.     

The Impact of Voice Disorders Among Teachers: Vocal Complaints, Treatment-Seeking Behavior, Knowledge of Vocal Care, and Voice-Related Absenteeism

Objectives

Teachers are at increased risk for developing voice disorders. Occupational risk factors have been extensively examined; however, little attention has been paid to the consequences of the vocal complaints. The objective of this study was to investigate the knowledge that teachers have about vocal care, treatment-seeking behavior, and voice-related absenteeism.

Methods

The study group comprised 994 teachers and 290 controls whose jobs did not involve vocal effort. All participants completed a questionnaire inquiring about vocal complaints, treatment-seeking behavior, voice-related absenteeism, and knowledge about vocal care. Comparisons were made between teachers with and without vocal complaints and with the control group.

Results

Teachers reported significantly more voice problems than the control population (51.2% vs 27.4%) (χ² = 50.45, df = 1, P < 0.001). Female teachers reported significantly higher levels of voice disorders than their male colleagues (38% vs 13.2%, χ² = 22.34, df = 1, P < 0.001). Teachers (25.4%) sought medical care and eventually 20.6% had missed at least 1 day of work because of voice problems. Female teachers were significantly more likely to seek medical help (χ² = 7.24, df = 1, P = 0.007) and to stay at home (χ² = 7.10, df = 1, P = 0.008) in comparison with their male colleagues. Only 13.5% of all teachers received information during their education.

Conclusions

Voice disorders have an impact on teachers' personal and professional life and imply a major financial burden for society. A substantial number of teachers needed medical help and was obligated to stay at home because of voice problems. This study strongly recommends the implementation of vocal education during the training of teacher students to prepare the vocal professional user.