Voice frequency change in singers and nonsingers

Trained singers and nonsingers vocally shadowed sequences of rapidly changing tones. Tone changes within the sequences were unpredictable in terms of direction and extent of frequency change. Subjects' responses to the shadowing task could be evaluated for accuracy of frequency matching, and for time and speed of voice frequency change. In addition, subjects' transitions between tones could be classified as hit, overshoot, undershoot, or oscillate. The two groups were equally accurate in matching the pitches of tones comprising the sequences. Similarly, pitch lowering was faster than pitch raising for both groups of subjects, while speeds for both lowering and raising increased with increases in size of the interval between tones. However, singers required less time than nonsingers in effecting transitions, apparently because they achieved faster peak speeds and took more direct paths between tones. Implications of the data for physiological and mechanical aspects of voice frequency control are discussed.     

Thyroplasty as primary and adjunctive treatment of glottic insufficiency

This study addresses the role of medialization thyroplasty in a variety of vocal fold pathological conditions manifested by glottic insufficiency. In this series, most patients had preceding or concurrent phonosurgical procedures. Success of surgery was determined by subjective, audioperceptual judgments, acoustic analysis, and vocal function measures. Vocal fold pathology played a greater role in determining success than did the presence or absence of adjunctive surgical procedures. Thyroplasty Type I was effective in treating glottic insufficiency in patients previously treated with various augmentation procedures as well as in those undergoing simultaneous reinnervation and arytenoid adduction. Technical factors predisposing to complications included violation of inner thyroid cartilage perichondrium, small shim size, sacrifice of cartilagenous window, and mucosal penetration. Thyroplasty should be considered as a primary or adjunctive treatment of patients with glottic insufficiency, especially when preservation of membranous vocal fold structure is of primary importance.     

The professional voice: Part III. Common diagnoses and treatments

Common problems that are of little consequence to other patients may be disabling to professional singers. Laryngologists must recognize even subtle manifestation of these ailments and be familiar with techniques to treat them without creating undesirable side effects. It is not usually necessary to restrict the trained professional from performing, and absolute voice rest is rarely necessary. Laryngeal surgery should be avoided whenever possible.     

Instrumental and Perceptual Evaluations of Two Related Singers

The primary goal of this study was to characterize a performer's singing and speaking voice. One woman was not admitted to a premier choral group, but her sister, who was comparable in physical characteristics and background, was admitted and provided a valuable control subject. The perceptual judgment of a vocal coach who conducted the group's auditions was decisive in discriminating these 2 singers. The singer not admitted to the group described a history of voice pathology, lacked a functional head register, and spoke with a voice characterized by hoarseness. Multiple listener judgments and acoustic and aerodynamic evaluations of both singers provided a more systematic basis for determining: 1) the phonatory basis for this judgment; 2) whether similar judgments would be made by groups of vocal coaches and speech-language pathologists; and 3) whether the type of tasks (e.g., sung vs. spoken) would influence these judgments. Statistically significant differences were observed between the ratings of vocal health provided by two different groups of listeners. Significant interactions were also observed as a function of the types of voice samples heard by these listeners. Instrumental analyses provided evidence that, in comparison to her sister, the rejected singer had a compromised vocal range, glottal insufficiencies as assessed aerodynamically and electroglottographically, and impaired acoustic quality, especially in her speaking voice.     

The effects of preventive vocal hygiene education on the vocal hygiene habits and perceptual vocal characteristics of training singers

The purpose of the present study was to determine the effects of vocal hygiene education on the vocal hygiene behaviors and perceptual vocal characteristics of untrained singers. Eleven adult untrained singers served as subjects. They attended four 1-hour class sessions on vocal hygiene, including anatomy and physiology of the phonatory mechanism, vocally abusive behaviors, voice disorders commonly seen in singers, and measures to prevent voice disorders. Pre- and postinstruction surveys were used to record subjects' vocal abuses and their perceptions of their speaking and singing voice. They also rated their perceived value of vocal hygiene education. Results revealed minimal changes in vocal hygiene behaviors and perceptual voice characteristics. The subjects did report a high degree of benefit and learning, however.     

Analysis of Voice and Quantitative Measurement of Glottal Gap After Thyroplasty Type I in the Treatment of Unilateral Vocal Paralysis

Thyroplasty type I is one of several surgical treatments in which improving the voice of unilateral vocal fold paralysis is the ultimate objective. The goal of the surgery is the medialization of the paralyzed vocal fold. The purpose of this study is to evaluate the effectiveness of thyroplasty type I through acoustical analysis, aerodynamic measures, and quantitative videostroboscopic measurements. We report on 20 patients with unilateral vocal cord paralysis who underwent thyroplasty type I. We performed preoperative and postoperative video image analysis (normalized glottal gap area) and computer-assisted voice analysis (fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, mean phonation time, mean flow rate, mean subglottic pressure) in all patients. The glottal gap was significantly reduced after thyroplasty type I. Postoperative voice quality was characterized by an improved pitch and amplitude pertubation (jitter and shimmer), phonation time (mean phonation time), and subglottic pressure (mean subglottic pressure). Thyroplasty type I is an effective method for regaining glottal closure and vocal function.     

A comparison of type I thyroplasty and arytenoid adduction

Glottal incompetence is a common laryngeal disorder causing impaired swallowing and phonation. The resultant voice has been characterized as weak and breathy with a restricted pitch range. Currently, medialization thyroplasty and arytenoid adduction are two of the surgical treatments for patients with glottal incompetence. However, few studies have evaluated the changes in objective measures of speech with type I thyroplasty and arytenoid adduction. In this study, 59 patients with glottal incompetence underwent either type I thyroplasty or arytenoid adduction. Acoustic (jitter, shimmer, and harmonics-to-noise ratio) and aerodynamic (airflow, subglottic pressure, and glottal resistance) measures were obtained both pre- and postoperatively. No significant differences were found among acoustic or aerodynamic measures for operation type. However, a significant pre/postsurgery effect was observed for translaryngeal airflow. In addition, no significant differences were found among the measures for patients with traditional compared with nontraditional operative indications. Patients who developed glottal insufficiency due to previous laryngeal surgery (e.g., vocal fold stripping) demonstrated no statistically significant improvement in acoustic or aerodynamic measures following thyroplasty or arytenoid adduction.     

Average speaking fundamental frequency in soprano singers with and without symptoms of vocal attrition

Nineteen trained soprano singers aged 18–30 years vocalized tasks designed to assess average speaking fundamental frequency (SFF) during spontaneous speaking and reading. Vocal range and perceptual characteristics while singing with low intensity and high frequency were also assessed, and subjects completed a survey of vocal habits/symptoms. Recorded signals were digitized prior to being analyzed for SFF using the Kay Computerized Speech Lab program. Subjects were assigned to a normal voice or impaired voice group based on ratings of perceptual tasks and survey results. Data analysis showed group differences in mean SFF, no differences in vocal range, higher mean SFF values for reading than speaking, and 58% ability to perceive speaking in low pitch. The role of speaking in too low pitch as causal for vocal symptoms and need for voice classification differentiation in vocal performance studies are discussed.     

Mechanical and dynamic aspects of voice production as related to voice therapy and phonosurgery

Laryngeal framework surgery can change the position and tensionof the vocal folds safely without direct surgical intervention in the vocal fold proper. Some 23 years of experience with phonosurgery have proved its usefulness in treating dysphonia related to unilateral vocal fold paralysis, vocal fold atrophy, and pitch-related dysphonias. Meanwhile, much information about the mechanism of voice production has been obtained through intraoperative findings of voice and fiberscopic examination of the larynx . Based on such knowledge together with information obtained through model experiments, the human vocal organ was reconsidered mainly from the mechanical view point, and the roles of voice therapy and singing pedagogy were discussed in relation to phonosurgery. The vocal organ may not be an ideal musical organ and is rather vulnerable, but its potential is enormous.     

The relationship among voice onset, voice quality, and fundamental frequency: a dynamical perspective

In dynamical motor theory, skill acquisition occurs as a modification of preexisting coordination patterns or attractor states. The purpose of this study was to assess how different levels of voice onset, voice quality, and fundamental frequency (F₀) combine to form the attractor states common to voice motor control. Three levels of voice onset (glottal, simultaneous, and breathy), voice quality (modal speech, mixed, and falsetto), and fundamental frequency (low, mid, and high) were manipulated by vocally untrained, female subjects. Percent correct of acquisition trials and self-report of effort were used as measures of stable phonations indicative of an attractor state. Using intensity as a covariate, the results provided support for two of the three predicted triads representing attractor states in female speakers: (1) glottal onset/modal speech quality/low F₀; and (2) breathy onset/falsetto quality/high F₀. The results of this study suggest that certain parameters of voice motor control, such as onset, quality, and F₀, exist as part of a dynamical system that can be identified and manipulated in voice motor acquisition and learning.     

Speaking fundamental frequency characteristics as a function of age and professional singing

The purposes of this project were to discover (1) if the speaking fundamental frequency (SFF) levels of professional singers differ significantly from those of nonsingers and (2) if the age-related SFF patterns are similar for these two classes of individuals. Sixty professional singers and 94 nonsingers were recorded reading the first paragraph of the “Rainbow Passage;” both males and females were included. Three paired groups (young, middle, and old age) were studied; they were selected on the basis of health and age. The professional singer groups were further divided by a binary voice classification system, specifically that of soprano/alto for women and tenor/baritone for men. It was found that the sopranos and tenors exhibited significantly higher SFF levels then did the age-matched nonsingers, whereas the altos and baritones did not differ significantly from the controls. Relationships within the performer groups were mixed. For example, there appeared to be a systemic trend for the sopranos and tenors to exhibit higher SFF levels than the altos and baritones. Finally, although the nonsinger SFF levels varied significantly as a function of age, those for the professional singers did not.     

Relationship between changes in voice pitch and loudness

Changes in mean fundamental frequency accompanying changes in loudness of phonation are analyzed in 9 professional singers, 9 nonsingers, and 10 male and 10 female patients suffering from vocal functional dysfunction. The subjects read discursive texts with noise in earphones, and some also at voluntarily varied vocal loudness. The healthy subjects phonated as softly and as loudly as possible at various fundamental frequencies throughout their pitch ranges, and the resulting mean phonetograms are compared. Mean pitch was found to increase by about half-semitones per decibel sound level. Grossly, the subject groups gave similar results, although the singers changed voice pitch more than the nonsingers. The voice pitch changes may be explained as passive results of changes of subglottal pressure required for the sound level variation.     

Voice quality after carbon dioxide laser and conventional surgery for T1A glottic carcinoma

The different types of small vocal fold tumor therapy allow the preservation of respiration and deglutition; the quality of phonation is the most important criterion for the patient. The aim of the study is to compare vocal function after treatment of T1a tumors by conventional and laser cordectomy. Fifty-seven male patients were included in the study: 27 underwent conventional cordectomy using an external approach, and 30 underwent an endoscopic microscopic laser cordectomy. Videolaryngoscopy was performed for each subject, and the maximal phonation time was measured. Spectrograms were recorded, and a perturbation analysis was performed if a clear harmonic structure was visible. Voices were perceptually rated by two experienced phoniatricians using the GRBAS scale. Even though a slightly better voice was found after conventional surgery throughout the data, no statistically significant difference was measured in the two groups. The data on voice outcome per se do not indicate the selection of one surgical approach over another.     

Frequency and risk factors for voice problems in teachers of singing and control subjects

Using a questionnaire format, 125 teachers of singing and 49 control subjects indicated whether they had a current or past voice problem, and provided information about their demographic characteristics, voice use patterns, and medication use. The results revealed similar rates of current voice problems reported by the two subject groups. However, teachers of singing were considerably more likely to report ever having had a voice problem than controls (64 vs. 33%). Risk factors were similar for the two groups. Dehydrating medications and a report of a past voice problem both increased the likelihood of perceiving a current problem, by a factor of three and five, respectively. Females were twice as likely to report a past voice problem as males, and younger subjects were slightly more likely to report a past problem as compared with older subjects. The implications of the findings are discussed from a theoretical as well as pragmatic perspective.