Throaty Voice Quality: Subglottal Pressure, Voice Source, and Formant Characteristics

"Throaty" voice quality has been regarded by voice pedagogues as undesired and even harmful. This study attempts to identify acoustic and physiological correlates of this quality. One male and one female subject read a text habitually and with a throaty voice quality. Oral pressure during p-occlusion was measured as an estimate of subglottal pressure. Long-term average spectrum analysis described the average spectrum characteristics. Sixteen syllables, perceptually evaluated with regard to throaty quality by five experts, were selected for analysis. Formant frequencies and voice source characteristics were measured by means of inverse filtering, and the vocal tract shape of the throaty and normal versions of the vowels [a,u,i,ae] of the male subject were recorded by magnetic resonance imaging. From this material, area functions were derived and their resonance frequencies were determined. The throaty versions of these four vowels all showed a pharynx that was narrower than in the habitually produced versions. To test the relevance of formant frequencies to perceived throaty quality, experts rated degree of throatiness in synthetic vowel samples, in which the measured formant frequency values of the subject were used. The main acoustic correlates of throatiness seemed to be an increase of F1, a decrease of F4, and in front vowels a decrease of F2, which presumably results from a narrowing of the pharynx. In the male subject, voice source parameters suggested a more hyperfunctional voice in throaty samples.     

Boot Camp: A Novel Intensive Approach to Voice Therapy

It is well known in the disciplines of neurobiology, exercise physiology, motor learning, and psychotherapy that desirable learning and behavior changes occur primarily from practice that involves high-intensity overload, variability, and specificity of training. We propose a novel treatment approach called intensive short-term voice therapy that uses these practice parameters for recalcitrant dysphonia. Intensive short-term voice therapy involves multiple sessions with a variety of clinicians, incorporating multiple simultaneous therapeutic approaches. The intensive short-term voice therapy approach is characterized by voice therapy for 1–4 successive days each with an average of 5 hours of therapy and five clinicians. This form of intensive voice therapy provides rigorous practice, involving not only overload but also opportunities for specificity and individuality thereby facilitating better transfer of learned skills. This article discusses the conceptual, theoretical, and practical foundations of this novel therapy approach.     

G. Paul Moore lecture: Rational thought: The impact of voice science upon voice care

Recent evolution in scientific knowledge and technology has led to monumental improvement in the standard of care for patients with voice disorders. New concepts in anatomy, physiology, measurement, and analysis have provided voice care professionals with not merely better understanding, but moreover an extensive vocabulary with which to think about voice function and dysfunction. Previously, we had to depend too much upon anecdote and “the art of medicine.” Thanks to scientific advances, we now have the tools we need for rational thought about the human voice. This is the fundamental change responsible for recent great advances in voice care.     

Twelve-Month Clinical Follow-Up Study of Voice Patients' Recovery Using the Voice Activity and Participation Profile (VAPP)

Objective

To study the effects of voice treatment including brief voice therapy for 12 months in two groups of voice patients: organic and functional.

Design and Methods

A clinical prospective follow-up study with repeated measurements in five phases: medical session, first voice therapy session, last voice therapy session, and 6 months and 12 months after voice therapy. The mean number of voice therapy sessions was 3.4. The main outcome measures were the Voice Activity and Participation Profile (VAPP) and the Symptom Questionnaire.Of consenting patients (n = 141) with chronic voice disorders, 46 dropped out during follow-up. Ninety-five patients formed the study group. Forty-one of them received only voice therapy, but the rest of them received combined treatment (medication, amplifiers, and voice massage), but also experienced life events affecting voice. Patients with any laryngeal pathology formed the organic group (n = 47), others had a functional voice disorder.

Results

Using the improvement criterion that the change of the VAPP score should exceed standard error of measurement, the percentage of individual patients achieving improvement was 47% in the mild, 59% in the moderate, and 75% in the severe disorder groups. Effect size for VAPP total score was 0.89. The positive effect continued to progress after the therapy ended. Patients with functional or organic voice disorder improved almost equally, although minor findings indicate that functional patients benefited more.

Conclusions

Voice treatment had a progressive effect for 1 year in half of our patients. No statistical difference was found between the functional and organic patient groups.     

Impact and Prevention of Voice Problems in the Teaching Profession: Embracing the Consumers'' View

Teachers are vulnerable to developing voice problems due to their specific occupational demands during teaching. Information on how the teaching profession is impacted by voice problems and what the profession perceives to be useful information for preventing voice problems is important for health care service providers. A total of 122 subjects from the teaching profession (55 practicing teachers and 67 prospective teachers) were therefore surveyed to ascertain their perception of their voice condition and the impact of voice problems on their communication, social life, personal emotions, and occupation. The results showed that the practicing teachers perceived their voice to be significantly worse than the prospective teachers. In addition, the teachers also faced significantly more difficulties in their daily communication than the prospective teachers. These two groups of subjects believed that information on breathing exercises and specific vocal hygiene strategies would help them prevent voice problems.     

Acoustic Changes in Student Actors' Voices After 12 Months of Training

This study was to evaluate acoustic changes in student actors' voices after 12 months of actor training. The design used was a longitudinal study. Eighteen students enrolled in an Australian tertiary 3-year acting program (nine male and nine female) were assessed at the beginning of their acting course and again 12 months later using a questionnaire, interview, maximum phonation time (MPT), reading, spontaneous speaking, sustained phonation tasks, and a pitch range task. Samples were analyzed for MPT, fundamental frequency across tasks, pitch range for speaking and reading, singing pitch range, noise-to-harmonic ratio, shimmer, and jitter. After training, measures of shimmer significantly increased for both male and female participants. Female participants' pitch range significantly increased after training, with a significantly lower mean frequency for their lowest pitch. The finding of limited or negative changes for some measures indicate that further investigation is required into the long-term effects of actor voice training and which parameters of voicing are most targeted and valued in training. Particular investigation into the relationship between training targets and outcomes could more reliably inform acting programs about changes in teaching methodologies. Further research into the relationship between specific training techniques, physiological changes, and vocal changes may also provide information on implementing more evidence-based training methods.     

Changes in Objective Acoustic Measurements and Subjective Voice Complaints in Call Center Customer-Service Advisors During One Working Day

SUMMARY: The aim of this study was to investigate how different acoustic parameters, extracted both from speech pressure waveforms and glottal flows, can be used in measuring vocal loading in modern working environments and how these parameters reflect the possible changes in the vocal function during a working day. In addition, correlations between objective acoustic parameters and subjective voice symptoms were addressed. The subjects were 24 female and 8 male customer-service advisors, who mainly use telephone during their working hours. Speech samples were recorded from continuous speech four times during a working day and voice symptom questionnaires were completed simultaneously. Among the various objective parameters, only F0 resulted in a statistically significant increase for both genders. No correlations between the changes in objective and subjective parameters appeared. However, the results encourage researchers within the field of occupational voice use to apply versatile measurement techniques in studying occupational voice loading.     

Normative Voice Range Profiles of Male and Female Professional Voice Users

Normative voice range profiles (VRP) are calculated for a group of male and female teachers, based on 43 and 46 recordings, respectively. All individuals had healthy voices. These normative VRPs contain 95% prediction intervals for both frequency and intensity. They are based on a series of mathematical transformations of the original individual VRPs in order to maintain in the normative VRPs the typical oval VRP shape, including the dip between modal and falsetto register. The normative VRPs presented are directly applicable in the clinical practice of otolaryngologists and speech-language pathologists.     

Voice profiles and standard voice profile of untrained children

Voice profiles were taken of 277 healthy children between the ages of 5 and 14 years. The measured phonetograms were grouped according to sex and years of age. In each group, the means and standard deviations of maximal and minimal volume of each frequency were calculated. The median was used to establish the upper and lower limits of the voice range of each group. No age-dependent changes of the group voice profiles were shown in the groups of 7 to 10 year olds. Out of that emerged a standard childhood voice profile of the untrained voice. After age 10, an increase of the dynamic range over the lowest frequencies was found. Because of the voice changes in puberty, a profile for 13- and 14-year-old boys could not be established.     

Vocal Range and Intensity in Actors: A Studio Versus Stage Comparison

A voice range profile (VRP) was obtained from each of eight professional actors and compared with two speech range profiles (SRPs). One speech profile was obtained during the dramatic reading of a scene in the laboratory and the other during a performance on stage in a professional theater. The objective was to determine the pitch and loudness ranges used by the actors in speech relative to the VRP. The principal question of interest was whether the actors stayed within the center of the VRP, or whether they tended to drift toward the boundaries of intensity and frequency. A second question was whether the performance within the laboratory accurately reflects that of a stage performance. The results suggest that some subjects tend to exceed the center of the VRP during the stage performance. It is hypothesized that these actors may stress their vocal mechanism during performance and are more likely candidates for vocal injury.     

Perceptual evaluation of voice quality and its correlation with acoustic measurements

To determine whether a correlation exists between the Grade, Roughness, Breathiness, Aesthenia, Strain (GRBAS) scale (a subjective measure of voice) and the Multi-Dimensional Voice Program (MDVP) scale (an objective measure of voice). A retrospective review of 37 voice patients (12 male/25 female) was conducted. Each voice was perceptually evaluated using the GRBAS scale by an experienced speech pathologist and acoustically analyzed using the MDVP scale. Statistical analysis using a multivariate regression model identified a significant correlation between the noise-related parameters of MDVP and the components of the GRBAS scale. Grade correlated with voice turbulence index (VTI), noise harmonic ratio (NHR), and soft phonation index (SPI). Roughness correlated with NHR only. Breathiness correlated with SPI only. Aesthenia also correlated with SPI only. Of the 19 acoustic variables measured by the MDVP system, only three noise parameters significantly correlated with the GRBAS perceptual voice analysis. Perhaps "noise" is the perceived acoustical quality of the dysphonic voice. A voice quantifying measure such as a "voice index score" could be proposed using the GRBAS scoring and the three clinically relevant MDVP values following further studies.     

Clinical applications of electroglottography

Electroglottography (EGG) is a method to monitor the vibrations of the vocal folds by measuring the varying impedance to a weak alternating current through the tissues of the neck. The paper is an attempt to give a state-of-the-art report of how electroglottography is used in the clinic. It is based on a search of the pertinent literature was well as on an inquiry to 17 well known specialists in the field. The EGG techniques are described and limitations to the method are pointed out. Attempts to document voice quality by EGG are recognized and computerized methods to obtain information about vibratory perturbations and/or the vibratory frequency of the vocal folds are described. The author's personal conclusion is that the EGG signal is especially well suited for measurements of the glottal vibratory period. In the clinic such measurements are useful for periodicity analysis, as a basis for recording intonation contours, and to establish the characteristics of the voice fundamental frequency.     

Movement of the velum during speech and singing in classically trained singers

The present study addresses two questions: (a) Is the action and/orposture of the velopharyngeal valve conducive to allow significant resonance during Western tradition classical singing? (b) How do the actions of the velo-pharyngeal valve observed in this style of singing compare with normal speech? A photodetector system was used to observe the area function of the velopharyngeal port during speech and classical style singing. Identical speech samples were produced by each subject in a normal speaking voice and then in the low, medium, and high singing ranges. Results indicate that in these four singers the velopharyngeal port was closed significantly longer in singing than in speaking samples. The amount of time the velopharyngeal port was opened was greatest in speech and diminished as the singer ascended in pitch. In the high voice condition, little or no opening of the velopharyngeal port was measured.     

Comparison of Singer's Formant, Speaker's Ring, and LTA Spectrum Among Classical Singers and Untrained Normal Speakers

Many studies have described and analyzed the singer's formant. A similar phenomenon produced by trained speakers led some authors to examine the speaker's ring. If we consider these phenomena as resonance effects associated with vocal tract adjustments and training, can we hypothesize that trained singers can carry over their singing formant ability into speech, also obtaining a speaker's ring? Can we find similar differences for energy distribution in continuous speech? Forty classically trained singers and forty untrained normal speakers performed an all-voiced reading task and produced a sample of a sustained spoken vowel /a/. The singers were also requested to perform a sustained sung vowel /a/ at a comfortable pitch. The reading was analyzed by the long-term average spectrum (LTAS) method. The sustained vowels were analyzed through power spectrum analysis. The data suggest that singers show more energy concentration in the singer's formant/speaker's ring region in both sung and spoken vowels. The singers' spoken vowel energy in the speaker's ring area was found to be significantly larger than that of the untrained speakers. The LTAS showed similar findings suggesting that those differences also occur in continuous speech. This finding supports the value of further research on the effect of singing training on the resonance of the speaking voice.     

Vocal Evaluation in Teachers With or Without Symptoms

The aim of this study was to perform voice evaluation in teachers with and without vocal symptoms, identifying etiologic factors of dysphonia, voice symptoms, vocal qualities, and laryngeal lesions. Eighty teachers were divided into two groups: GI (without or sporadic symptoms, 40) and GII (with frequent vocal symptoms, 40). They answered a specific questionnaire, and were subject to a perceptual vocal assessment (maximum phonation time, glottal attack, resonance, coordination of breathing and voicing, pitch, and loudness), GIRBAS scale, and to videolaryngoscopy. Females were predominant in both groups, and the age range was from 36 to 50 years. Elementary teachers predominated, working in classes with 31-40 students. Voice symptoms and alterations in the perceptual vocal analysis and in the GIRBAS scale were more frequent in GII. In 46 teachers (GI-16; GII-30), videolaryngoscopy exams were abnormal with the vocal nodules being the most frequent lesions. These results indicate that a teacher's voice is compromised, and requires more attention including control of environmental factors and associated diseases, preventive vocal hygiene, periodic laryngeal examinations, and access to adequate specialist treatment.