Voice Evaluation

CHAPTER 58 Voice Evaluation

Voice is produced by interactions among the respiratory, laryngeal, and resonance systems. The speech-language pathologist’s voice evaluation is multifactorial, assessing each system in addition to the speech output. The purpose of this chapter is to describe the typical components of a voice evaluation and how to interpret the results. The focus of this chapter is on the perceptual, physical, and physiologic evaluation; the patient history and videostroboscopy are detailed in other chapters.

Both clinical and research requirements factor into decisions on how to measure voice. In the clinical arena, vocal function measures are used in both the diagnosis and treatment of voice disorders. Vocal function testing helps clinicians document the status of the voice source and the supraglottic vocal tract, characterize the type and severity of the voice disorder, and explain discrepancies between voice quality and stroboscopic evaluation by providing cycle-to-cycle information that is not available with stroboscopy. Vocal function measures can help the voice care team determine treatment goals and can be used as visual feedback during behavioral treatment. Repeated testing over time allows clinicians to monitor and document changes that result from treatment and also to monitor disease progression or recurrence. From a research perspective, voice measurements can improve our understanding of voice production, help identify links between laryngeal disease and voice production, and document change with interventions.

Many of the instrument-based tests yield numbers that lead some clinicians to view the results as “objective”; however, examiners influence results through their specific instructions to the individual as well as the selection of stimulus, token, measure, and equipment. In addition, the testing environment, time of day, day of week, and the number and type of prior tests conducted on the same individual can affect measurements. Results of vocal function testing should, therefore, be interpreted with these considerations in mind. To be considered reliable, measures must be made with the use of standard protocols, recording procedures, patient instructions, and test environments. Because of the multidimensional nature of the voice, one measure cannot adequately characterize an individual’s voice. Thus, a group of measures is frequently selected to capture the primary elements of the voice, such as pitch, loudness, and quality.

The following discussion describes a typical voice evaluation, with a focus on how to interpret the results. The evaluation is divided into the following categories: patient scales, perceptual evaluation, measures, and diagnostic therapy. Within each category, measures can reflect typical voice use or maximum performance capabilities. The particular measures performed vary from one speech-language pathologist to the next, depending on equipment available as well as on the examiner’s education and philosophy.

Patient Scales

Individuals have different requirements and expectations of their voices; thus, the same level of dysphonia can differentially limit participation in typical daily activities. As part of a complete voice evaluation, the effect of the voice problem on each individual’s life should be assessed. Patient measures are scales completed by the patient and sometimes a caregiver or significant other. These scales typically measure patient satisfaction, quality of life, general health, handicap or loss as a result of the voice disorder, or some aspect of voice production (e.g., ease of phonation, effort, quality). Several scales specific to voice have been published in the last decade. The scales vary in length, construction, and what they assess.

Each published scale measures a different aspect of the voice. Some scales were constructed more carefully than others, so reliability and validity characteristics differ. Scale selection should be made according to variables of interest and reliability requirements. In general, patient scales are a wonderful addition to a voice evaluation and provide novel information about the patient’s point of view. A patient scale can guide discussion between health care providers and patients and help the team determine treatment goals.

Two commonly used scales, the Voice Handicap Index (VHI)1 and Voice-Related Quality of Life (V-RQOL),2 are described here. Details and information about scale construction can be found in the reference articles, and a synopsis of current scales can be found in Table 58-1.

Voice Handicap Index

The Voice Handicap Index was designed to assess handicap, “a social, economic, or environmental disadvantage resulting from an impairment or disability.”3 The instrument consists of 30 statements that patients rate on a 5-point equal-appearing interval scale that reflects the frequency of occurrence. The total possible score is 120, with higher scores reflecting greater handicap. Although the initial publication suggests division into functional, physical, and emotional subscales,1 other writers have questioned the subscale structure,4,5 suggesting that total score appears more meaningful. Since its publication in 1997, the Voice Handicap Index has been widely used to show voice handicap in specific groups of patients, comparisons between handicap and vocal function measures, and change with treatment.

Other Patient Scales

The Voice Symptom Scale (VoiSS)4,6 is a psychometrically sound 30-item scale representing physical impairment, emotional response, and related physical symptoms. The Voice Activity and Participation Profile (VAPP)7 follows the terminology and framework of the World Health Organization’s 1997 revision8 of the International Classification of Functioning, Disability, and Health. Patients indicate their extent of limitation in daily activities and restriction of participation in corresponding activities.

The Reflux Symptom Index (RSI), the Patient Questionnaire of Vocal Performance (VPQ), and the Voice Outcome Survey (VOS) are more limited in scope. The Reflux Symptom Index, made up of 9 items, is designed to document patient symptoms of laryngopharyngeal reflux.9 The Patient Questionnaire of Vocal Performance is a 12-item scale designed to assess the physical, social, and emotional impacts of a nonorganic voice disorder.10,11 The Voice Outcome Survey is a 5-item survey designed for patients with unilateral vocal fold paralysis.12

Perceptual Evaluation

Auditory Perceptual Assessment

Several formal measures and scales have been proposed to rate voice quality; two of the most commonly used scales are described here. Auditory perceptual ratings are appealing because the ultimate goal of voice treatment is to improve perceived voice quality. Unfortunately, such measures are fraught with definition, rating, and interpretation difficulties. Voice quality is difficult to define, leading to many, often circular, definitions of each term. Raters have different internal representations of the parameters and severity. It is difficult to differentiate between related qualities, and univariate ratings do not often correlate well with global ratings or measurements (for a detailed discussion, see Kreiman and Gerratt13). Although auditory perceptual assessment often results in a number, the number represents a perceptual judgment rather than a measurement and should be treated accordingly.


GRBAS is a well-known standard scale that was developed by the Committee for Phonatory Function of the Japanese Society of Logopedics and Phoniatrics. As described by Hirano,14 the G represents grade or overall quality. The other four letters represent dimensions of voice quality, as follows: R for roughness, B for breathiness, A for asthenia, and S for strain. Descriptions of each parameter are given in Table 58-2. Each parameter is rated on a 4-point scale: 0 means that there is no deficit in this parameter, 1 is a mild deficit, 2 is a moderate deficit, and 3 indicates a severe deficit. There is no standard recommendation for the type of utterance(s) to use with GRBAS, so specific information about testing conditions should be documented in the report.

Table 58-2 GRBAS Scale for Auditory-Perceptual Evaluation

Parameter Hirano Definition* National Center for Voice and Speech Definition
Grade (G) Overall severity  
Roughness (R) Psychoacoustic impression of irregular vocal-fold vibration An uneven, bumpy quality that appears to be unsteady in the short term but stationary in the long term; acoustically, the waveform is often aperiodic, with the modes of vibration lacking synchrony, but voices with subharmonics can also be perceived as rough.
Breathiness (B) Psychoacoustic impression of air leakage through the glottis Containing the sound of breathing (expiration) during phonation; acoustically, breathy voice, like falsetto, has most of its energy in the fundamental, but a significant component of noise is present owing to turbulence in the glottis. In hyperfunctional breathiness, air leakage may occur in various places along the glottis, whereas in normal voice, air leakage is usually at the vocal processes.
Asthenia (A) Weakness or lack of power in the voice A voice that appears too low in effort, weak; hypofunction of laryngeal muscles is apparent.
Strain (S) Psychoacoustic impression of a hyperfunctional state of phonation A voice that appears effortful; visually, hyperfunction of the neck muscles is apparent; the entire larynx seems compressed.

* From Hirano M. Clinical Examination of Voice. New York: Springer-Verlag; 1981.

From Titze IR. Workshop on Acoustic Voice Analysis: Summary Statement. Iowa City, IA: National Center for Voice and Speech; 1995.


The Consensus Auditory-Perceptual Evaluation–Voice (CAPE-V) was developed at a 2003 consensus conference sponsored by the American Speech-Language-Hearing Association Special Interest Division 3, Voice and Voice Disorders.15 Six core and additional examiner-selected parameters are rated on a visual analog scale. The clinician uses a tick mark to rate function on a 100-mm line and then measures the distance from the left end of the line to establish a score; higher scores reflect a more severe deviation from normal quality. Core parameters are overall severity, roughness, breathiness, strain, pitch, and loudness. The judged parameters are identified as consistent or intermittent, and resonance differences can be noted. The CAPE-V is to be scored from two sustained vowels, six standard sentences, and at least 20 seconds of natural running speech. Recommendations about testing and recording environments are included.

Visual Perceptual Examination

The visual perceptual examination refers to visible and physical aspects of voice production related to etiology, maintenance, or effect of dysphonia. Koschkee and Rammage16 have divided the visual perceptual examination into the following five categories: (1) general appearance; (2) posture, breathing, and musculoskeletal tension; (3) neurologic dysfunction; (4) physical dysmorphology; and (5) clinical manifestations of disease. Several components of the visual perceptual evaluation are described in more detail here.

General appearance factors, such as apparent age, height and weight, facial expression, skin, hair, and nails, personal hygiene and dress, and head and neck observations, can be indicative of underlying systemic disease, previous treatment, or emotional disorder. One example is the masked face of parkinsonism.

Posture, breathing, and musculoskeletal tension are key components of a voice evaluation because they frequently affect pitch, loudness, and quality. Postural assessment likely involves information about the alignment of the head, neck, torso, pelvis, and legs. Visual assessment of breathing includes observations of neck, shoulder, chest, and abdominal movement. Reports of musculoskeletal tension contain information about extent of jaw motion, chin jut, neck extension, bulging of the neck muscles while talking, or raised shoulders.

Neurologic dysfunction is indicated by observations such as unsteadiness, asymmetry, rigidity, hesitation, slowness, weakness, incoordination, inconsistency, and extraneous movements. Weakness, asymmetry, and incoordination of the tongue, jaw, lips, or soft palate are especially noteworthy. The presence of focal dystonias, such as writer’s cramp, blepharospasm, torticollis, and oromandibular dysphonia, usually leads the examiner to consider a neurologically based voice disorder, such as spasmodic dysphonia.

Tactile Perceptual Evaluation

The manual examination of laryngeal musculoskeletal tension includes palpation of the suprahyoid muscles, the major horns of the hyoid bone, the superior cornu and the lateral aspects of the thyroid cartilage, the thyrohyoid space, and the anterior border of the sternocleidomastoid muscle. It is useful to assess suprahyoid tension and thyrohyoid space both at rest and during phonation. The examiner should also attempt to move the thyroid cartilage from side to side.1719 Figure 58-1 depicts this evaluation. Some authors recommend palpating the thyrohyoid, cricothyroid, and pharyngolaryngeal (inferior constrictor and posterior cricoarytenoid) muscles as well.20,21 Normal findings include palpable space between the hyoid bone and the superior border of the thyroid cartilage and mobility of the laryngeal complex. Findings indicative of excessive musculoskeletal tension include pain with palpation (frequently more severe on one side), decrease or absence of thyrohyoid space at rest or with phonation, muscle “knots,” high carriage of the hyoid bone and thyroid cartilage, and difficulty rotating the larynx.1721

A drawback of the examination is that it is subjective, and examiner’s skill and experience likely affect ratings. In addition, there are currently no intra- or inter-examiner reliability data for the technique, and the sensitivity and specificity of abnormal findings are unknown. Even given these limitations, tactile perceptual evaluation is a powerful technique to rapidly assess the contribution of muscle tension to the observed voice quality. Teasing apart the muscle tension and other components of the dysphonia can help ensure proper diagnosis and management; the tactile examination is one tool used in this endeavor.


Many different types of measurements can be used in the voice evaluation to describe pitch, loudness, and quality. Most speech-language pathologists use a subset of these measures, depending on their particular philosophy, education, and the equipment available to them. The measures described here are grouped into several categories based on measurement technique: chest wall displacement, aerodynamic assessment, and acoustic analysis. A fourth category, vocal fold measures, includes noninvasive evaluation techniques designed to assess vocal fold vibration patterns.

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Jun 5, 2016 | Posted by in OTOLARYNGOLOGY | Comments Off on Voice Evaluation

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