CHAPTER 1 Introduction: The Voice Diagnostic Protocol and Initial Stages of the Diagnostic Process The goal ofthis book is to provide detailed information re­ • It is not a book dealing with the method and interpreta­ garding the rationale and procedures for an array ofrelatively tion of laryngoscopy or stroboscopy. Although these are low-cost and readily available methods ofvoice analysis that important elements of a voice diagnostic, most clini­ will be collectively referred to as the Voice Diagnostic Pro­ cians do not have the trainingInc. and/or the equipment to tocol (VDP). A protocol may be defined as a set of methods carry out these procedures. In addition, when done for or procedures by which a clinical study may be carried out. diagnostic purposes, it is essential that visualization of By stressing the use of relatively low-cost methods, it is the larynx be carried out by an otolaryngologist familiar the intention of this book to provide detailed information with laryngeal disorders, who will then make an ap­ and instruction on methods that can be used by any speech propriate medical diagnosis and recommendations. It is pathologist in any situation or environment. Although it is expectedPRO-ED, that the clinician reading this book will seek hoped that all readers interested in the study of voice evalu­ appropriateby referral sources for laryngoscopic evalua­ ation procedures will benefit from the content of this book, tion (as well as stroboscopy, ifnecessary). it is particularly designed as a resource for (1) graduate • This is not a book dealing with instrumentation methods students in speech-language pathology and (2) practicing such as electroglottography (EGG), advanced aerody­ speech-language pathologists interested in expanding their namic assessment, or electromyography (EMG). Al­ skills in voice diagnosis. though these methods may add valuable information The VDP provides the clinician with a detailed and com­materialto our assessment of vocal function, they require an prehensive assessment of voice function, incorporating ele­ expense and expertise with instrumentation that may ments of patient history, perceptual assessment, acoustic make them clinically unfeasible in many situations. methods, and important estimates of physiological activity. By focusing solely on voice diagnostic procedures, it is the Although many ofthe tasks discussed in this protocol will intention of this book to illuminate methods that are often appear "simple" or uncomplicated on the surface, review of "buried" or discussed in a cursory manner in more general the theoretical background ofthese tasks, descriptions in the voice texts. However, focus on acopyrighted single topic necessarily literature, issues of validity and reliability, etc., make even means that certain associated© areas of study will not be "simple" procedures quite complex in terms of clinical use included: and interpretation. Therefore, the background information provided in this book is believed to be necessary if the • This is not a book dealing with resonance-based disor­ clinical information gathered from these tasks is to be rea­ ders such as velopharyngeal inadequacylincompetence sonably interpreted and used with maximum effectiveness. and associated speech characteristics such as hypema­ Even though many of the tasks incorporated in the VDP use sality and hyponasality and nasal emission. This book instrumentation methods, they cannot really be judged to deals with "voice" as a phonatory event, with focus be objective in nature. True objective measures would be primarily on laryngeal and respiratory mechanisms. independent ofhuman error, judgment, perceptions, and bias • Although aspects ofthis book will necessarily deal with of the clinician (Behrman & Orlikoff, 1997; Nicolosi, Har­ elements of laryngeal anatomy, phonatory physiology, ryman, & Kresheck, 1989). In addition, an ideal objective and acoustic principles, it is not an anatomy or speech test would also be independent of influence from patient science text. behavior (i.e., the patient would not be able to influence 2 THE VOICE DTAGl\OSTIC PROTOCOL test results as a function of his or her immediate behavior). sures of voice and the underlying physiology of phonation. In the case of many instrumental tasks of vocal function, It is not enough to simply recognize that a patient has a the ways in which measures are obtained and interpreted rough-sounding voice, higher than expected fundamental are subjective in nature and affected by both clinician and frequency, or short maximum phonation time-the clinician patient (Behrman & Orlikoff, 1997). must develop a rational hypothesis as to why the patient has certain characteristics. This is where application of our THE CONCEPT OF DIAGNOSIS VS. ASSESSMENT! knowledge ofthe underlying physiology or pathophysiology EVALUATION affecting voice production comes into play. A number of previous works dealing with diagnosis of voice disorders The title of this book clearly indicates that the procedures have also stressed this point. Murry (1982) stated that "the described herein are to be components of a diagnostic pro­ assessment of the vocal mechanism ...encompasses a de­ tocol. The term diagnostic has been specifically used to tailed analysis of the abnormal physiologic behavior of indicate that the outcome ofthis process will achieve several the laryngeal mechanism, specifically, and the relationship important goals: between the behavior of the laryngeal mechanism and the patient's general speech and voice production" (p. 478). 1. Our diagnostic decisions will be based on a synthesis Bless and Hicks (1996) stated that "assessment of vocal ofinformation from diverse areas all dealing with as­ function has evolved to mean deriving a description of voice pects of voice function, such as anatomy and physiol­ production...that allows clinicians to make inferences about ogy, acoustics, perception, psychometrics, and knowl­ the functioning of the underlying anatomical and physi­ edge of norms and testing techniques. Inc. ological condition of the larynx" (p. 124). Behrman and 2. The final diagnosis will be derived from the ability Orlikoff (1997) go so far as to stress that "the underlying to distinguish the patient's problem from a large field pathophysiology is [italics added] the voice disorder that the ofpossibilities (Haynes, Pindzola, & Emerick, 1992). clinician must seek to understand" (p. 10). This process is referred to as dijJerential diagnosis, a Once the clinician can hypothesize the possible causative process that takes into account all significant variables factors (behavioral or organic) underlying the patient's voice contributing to the disorder and attempts to differenti­ PRO-ED, disorder, the development of treatment goals becomes evi­ ate the presenting problem from related or dissimilar dent. A physiological approach to diagnosis should lead problems (Weinberg, 1983). by to physiological voice therapy, in which "the management 3. The final diagnosis will actually be the beginning of approach is a direct modification ofthe inappropriate physi­ a continuous venture that will be open to revision on ologic activity" (Stemple, 1993, p. 4). It is clear that the the basis ofthe patient's future behavior. success of voice therapy is highly dependent on the skill Some may object to the use of the term diagnosismaterial or and inferences ofthe voice clinician derived from the initial diagnostic as used by speech-language pathologists, perhaps diagnosis. because of (1) the association of the term with the medical profession and (2) the possible implication that the speech­ AVOIDANCE OF MEDICAL DIAGNOSTIC TERMS language pathologist will be carrying out a medical proce­ dure. Some would prefer the use of terms such as assess­ The focus of the speech pathologist involved in the voice ment or appraisal to describe our methods. However, these diagnostic should be to assess voice production, identify terms are not synonymous with diagnosis and describe only possible underlying factors (behavioral and/or organic) that the procedures used within the overallcopyrighted diagnostic method. may be responsible for the cause and maintenance of the In contrast, "diagnosis requires© placing measurements and voice problem, and determine the severity ofthe voice prob­ other observational data into context and perspective in order lem (Behrman & Orlikoff, 1997; Colton & Casper, 1996; to decide whether a problem exists and to differentiate one Murry, 1982). Itis not the speech pathologist's responsibility problem from others which may have similar performance to determine the specific existence and type of pathological aspects" (Peterson & Marquardt, 1990, p. 4). It is my belief condition that may be affecting the phonatory function ofthe that the term diagnosis is a universal term that describes patient (Behrman & Orlikoff, 1997; Murry, 1982). Although a process of investigation and deduction that cannot be the literature is ripe with the perceptual and acoustic de­ reserved for a particular field or profession. scription of various pathological states, the voice clinician should focus his or her diagnostic conclusions on possible A PHYSIOLOGICAL VIEW OF VOICE DIAGNOSIS physiological mechanisms that may be responsible for the various perceptual, acoustic, and other signs observed in The various sections of this book will stress the possible the particular patient rather than on diagnostic labels. This relationships between perceptual, acoustic, and other mea­ description