El lado emocional o espiritual del liderazgo

Voice therapy for adults may be motivated by func-tional, health-related, or diagnostic considerations.

Functional issues are the usual indication. Adults with voice problems often experience significant functional disruptions in occupational, social, communicative, physical, or emotional domains, and in selected

popula-tions, voice therapy is e¤ective in reducing such dis-ruptions. Health-related concerns are less common precipitants of voice therapy in adults. However, physi-cal disease such as cancerous, precancerous, inflam-matory, or neurogenic disease may exist and may be exacerbated by behavioral factors such as smoking, diet, hydration, or phonotrauma. Voice therapy may be a useful adjunct to medical or surgical treatment in these cases. Finally, voice therapy may be indicated in cases of diagnostic uncertainty. A classic situation is the need to distinguish between functional and neurogenic con-ditions. The restoration of a normal or near-normal voice with therapy may suggest a functional origin of the problem. Lack of voice restoration suggests the need for further clinical studies to rule out neurological causes.

Voice therapy can be characterized with reference to several di¤erent classification schemes, which results in a certain amount of nosological confusion. Many of the conditions listed in the various classifications map to several di¤erent voice therapy options, and by the same token, each therapy option maps to multiple classifications. Here we review voice therapy in relation to (1) vocal biomechanics and (2) a specific therapy approach—roughly the ‘‘what’’ and ‘‘how’’ of voice therapy.

Vocal Biomechanics. The preponderance of voice problems that are amenable to voice therapy involve some form of abnormality in vocal fold adduction. Pho-notraumatic lesions such as nodules, polyps, and non-specific inflammation consequent on voice use are traceable to hyperadduction resulting from vocal fold impact stress. Adduction causes monotonic increases in impact stress (Jiang and Titze, 1994). In turn, impact stress appears to be a primary cause of phonotrauma (Titze, 1994). Thus, therapy targeting a reduction in adduction is indicated in cases of hyperadduction. An-other large group of diagnostic conditions involves hypoadduction of the vocal folds. Examples include vocal fold paralysis, paresis, atrophy, bowing, and non-adducted hyperfunction (muscle tension dysphonia; for a discussion, see Hillman et al., 1989). Treatment that increases vocal fold closure is indicated in such cases.

Voice therapy addresses adductory deviations using a variety of biomechanical solutions. The traditional ap-proach to hyperadduction and its sequelae has targeted the use of widely separated vocal folds and small-amplitude oscillations during voice production; exam-ples are use of a ‘‘quiet, breathy voice’’ (Casper et al., 1989; Casper, 1993) or quiet ‘‘yawn-sigh’’ phonation (Boone and McFarlane, 1993). This general approach is sensible for the reduction of hyperadduction and thus phonotraumatic changes, in that vocal fold impact stress, and phonotrauma, should be reduced by it. There is evidence that the quiet, breathy voice approach is e¤ective in reducing signs and symptoms of phono-traumatic lesions for individuals who use it outside the clinic (Verdolini-Marston et al., 1995). However, indi-viduals may also restrict their use of a quiet, breathy voice extraclinically because it is functionally limiting (Verdolini-Marston et al., 1995).

The traditional approach to hypoadduction has in-volved ‘‘pushing’’ and ‘‘pulling’’ exercises, which should reduce the glottal gap (e.g., Boone and McFarlane, 1994). Indeed, some data corroborate clinicians’ impres-sions that this approach can increase voice intensity in individuals with glottal incompetence (Yamaguchi et al., 1993).

A more recent approach to treating adductory abnormalities has focused on the use of a single ‘‘ideal’’

vocal fold configuration as the target for both hyper-adduction and hypohyper-adduction. The configuration in-volves barely separated vocal folds, which is ‘‘ideal’’

because it optimizes the trade-o¤ between voice output strength (relatively strong) and vocal fold impact stress, and thus reduces the potential for phonotraumatic injury (Berry et al., 2001). Voice produced with this intermedi-ate laryngeal configuration has been called ‘‘resonant voice,’’ perceptually corresponding to anterior oral vibratory sensations during ‘‘easy’’ voicing (Verdolini et al., 1998). Programmatic approaches to resonant voice training have shown reductions in phonatory ef-fort, voice quality, and laryngeal appearance (Verdolini-Marston et al., 1995), as well as reductions in functional disruptions due to voice problems in individuals with conditions known or presumed to be related to hyper-adduction, such as nodules. Moreover, there is evidence that individuals use this type of voicing outside the clinic more than the traditional ‘‘quiet, breathy voice’’ because it is functionally tractable (Verdolini-Marston et al., 1995). Resonant voice training may also be useful in improving vocal and functional status in individuals with hypoadducted dysphonia. Recent theoretical mod-eling has indicated that nonlinear source (vocal fold)–

filter (vocal tract) interactions are critical in maximizing voice output germane to resonant voice and other voice types (Titze, 2002).

A relatively small number of clinical cases involve vocal fold elongation abnormalities as the salient feature of the vocal condition. Often, the medical condition in-volves cricothyroid paresis, although thyroarytenoid pa-resis may also be implicated. Voice therapy has been less successful in treating such conditions. Other elongation abnormalities are functional, as in mutational falsetto.

The clinical consensus is that voice therapy generally is useful in treating mutational falsetto.

Finally, in addition to addressing laryngeal kinemat-ics, voice therapy usually also addresses nonphonatory aspects of biomechanics that influence the vocal fold mucosa. Such issues are addressed in voice hygiene pro-grams (see voice hygiene). Mucosal performance and mucosal vulnerability to trauma are the key concerns.

The primary issues targeted are hydration and behav-ioral control of laryngopharyngeal reflux. Dehydration increases the pulmonary e¤ort required for phonation, whereas hydration decreases it and also decreases laryn-geal phonotrauma (e.g., Titze, 1988; Verdolini, Titze, and Fennell, 1994; Solomon and DiMattia, 2000). Thus, hydration regimens are appropriate for individuals with voice problems and dehydration (Verdolini-Marston, Sandage, and Titze, 1994). There is increasing support for the view that laryngopharyngeal reflux plays a role in

a wide range of laryngeal diseases, including inflamma-tory and even neurogenic and malignant disease. Voice therapy can play a supportive role to the medical or surgical treatment of laryngopharyngeal reflux by edu-cating patients regarding behavioral issues such as diet and sleeping position. Some data are consistent with the view that control of laryngopharyngeal reflux can im-prove both laryngeal appearance and voice symptoms in individuals with a diagnosis of laryngopharyngeal reflux (Shaw et al., 1996; Hamdan et al., 2001). However, vo-cal hygiene programs alone in voice therapy apparently produce little benefit if they are not coupled with voice production work.

Specific Therapy Approach. Recently, interest has emerged in cognitive mechanisms involved in skill ac-quisition and factors a¤ecting patient compliance as related to voice training and therapy models. Speech-language pathologists may train individuals to acquire the basic biomechanical changes described in preceding paragraphs, and others. The traditional approach is eclectic and entails implementing a series of facilitating techniques such as the ‘‘yawn-sigh’’ and ‘‘push-pull’’

techniques, as well as other maneuvers, such as altering the tongue position, changing the loudness of the voice, using chant talk, and using digital manipulation. Facili-tating techniques are used by many clinicians and are generally considered e¤ective. However, formal e‰cacy data are lacking for most of the techniques. An ex-ception is digital manipulation, specifically manual circumlaryngeal therapy (laryngeal massage), used for idiopathic, presumably hyperfunctional dysphonia. Brief courses of aggressive laryngeal massage by skilled prac-titioners have dramatically improved voice in individuals with this condition (Roy et al., 1997). Also, variants of

‘‘yawn-sigh’’ phonation, such as falsetto and breathy voicing, may temporarily improve symptoms of adduc-tory spasmodic dysphonia and increase the duration of the e¤ectiveness of botulinum toxin injections (Murry and Woodson, 1995).

Several programmatic approaches to voice therapy have been developed, some of which have been sub-mitted to formal clinical studies. An example is the Lee Silverman Voice Treatment (LSVT). This treatment uses

‘‘loud’’ voice to treat not only hypoadduction and hypophonia, but also prosodic and articulatory deficien-cies in individuals with Parkinson’s disease. LSVT uti-lizes a predetermined hierarchy of speech tasks in 16 therapy sessions delivered over 4 weeks. In comparison with control and alternative treatment groups, LSVT has increased vocal loudness and voice inflection for as long as 2 years following therapy termination (Ramig, Sapir, Fox et al., 2001; Ramig, Sapir, Coun-tryman et al., 2001). Critical aspects of LSVT that may contribute to its success include a large number of repe-titions of the target ‘‘loud voice’’ in a variety of physical contexts.

Another programmatic approach to voice therapy, the Lessac-Madsen Resonant Voice Therapy (LMRVT), was developed for individuals with either hyper- or hypoadducted voice problems associated with nodules, Voice Therapy for Adults 89

polyps, nonspecific phonotraumatic changes, paralysis, paresis, atrophy, bowing, and sulcus vocalis. LMRVT targets the use of barely touching or barely separated vocal folds for phonation, a configuration considered to be ideal because it maximizes the ratio of voice output intensity to vocal fold impact intensity (Berry et al., 2001). In LMRVT, eight structured therapy sessions typically are delivered over 8 weeks. Training empha-sizes sensory processing and the extension of ‘‘resonant voice’’ to a variety of communicative and emotional environments. Data on preliminary versions of LMRVT indicate that it is as useful as quiet, breathy voice train-ing for sorority women with phonotrauma or the use of amplification for teachers with voice problems in reducing various combinations of phonatory e¤ort, voice quality, laryngeal appearance, and functional sta-tus (Verdolini-Marston et al., 1995).

Another programmatic approach to voice therapy for both hyper- and hypoadducted conditions is called Vocal Function Exercises (VFE; Stemple et al., 1994). This approach targets similar vocal fold biomechanics as LMRVT, that is, vocal folds that are barely touching or barely separated, for phonation. Training consists of repeating maximally sustained vowels and pitch glides twice daily over a period of 4–6 weeks. Carryover exer-cises to conversational speech may also be used. A 6-week program of VFE in teachers with voice problems resulted in greater self-perceived voice improvement, greater phonatory ease, and better voice clarity than that achieved with vocal hygiene treatment alone (Roy et al., 2001).

Another program, Accent Therapy, addresses the ideal laryngeal configuration—barely touching or barely separated vocal folds—in individuals with hyper- and hypoadducted conditions (Smith and Thyme, 1976).

Training entails the use of specified rhythmic, prosodi-cally stressed vocal repetitions, beginning with sustained consonants and progressing to phrases and extended speech. The Accent Method is more widely used in Eu-rope and Asia than in the United States.

Electromyographic biofeedback has been reported to be e¤ective in reducing laryngeal hyperfunction and la-ryngeal appearance in individuals with voice problems linked to hyperadduction (nodules). Also, visual feed-back using videoendoscopy may be useful in treating numerous voice conditions; specific clinical observa-tions have been reported relative to ventricular phona-tion (Bastian, 1987).

Finally, some clinicians have found that sensory di¤erentiation exercises may help in the treatment of repetitive strain injury—one of the fastest growing oc-cupational injuries. Repetitive strain injury involves decreased use of manual digits or voice and pain subse-quent to overuse. Attention to sensory di¤erentiation in the treatment of repetitive strain injury is motivated by reports of fused representation for groups of movements in sensory cortex following extensive digit use (e.g., Byl, Merzenich, and Jenkins, 1996).

—Katherine Verdolini

References

Bastian, R. W. (1987). Laryngeal image biofeedback for voice disorder patients. Journal of Voice, 1, 279–282.

Berry, D. A., Verdolini, K., Montequin, D. W., Hess, M. M., Chan, R. W., and Titze, I. R. (2001). A quantitative output-cost ratio in voice production. Journal of Speech-Language-Hearing Research, 44, 29–37.

Boone, D. R., and McFarlane, S. C. (1993). A critical view of the yawn-sigh as a voice therapy technique. Journal of Voice, 7, 75–80.

Boone, D. R., and McFarlane, S. C. (1994). The voice and voice therapy (5th ed.). Englewood Cli¤s, NJ: Prentice Hall.

Byl, N. N., Merzenich, M. M., and Jenkins, W. M. (1996). A primate genesis model of focal dystonia and repetitive strain injury: I. Learning-induced dedi¤erentiation of the repre-sentation of the hand in the primary somatosensory cortex in adult monkeys. Neurology, 47, 508–520.

Casper, J. K. (1993). Objective methods for the evaluation of vocal function. In J. Stemple (Ed.), Voice therapy: Clinical methods (pp. 39–45). St. Louis: Mosby–Year Book.

Casper, J. K., Colton, R. H., Brewer, D. W., and Woo, P.

(1989). Investigation of selected voice therapy techniques.

Paper presented at the 18th Symposium of the Voice Foun-dation, Care of the Professional Voice, New York.

Hamdan, A. L., Sharara, A. I., Younes, A., and Fuleihan, N.

(2001). E¤ect of aggressive therapy on laryngeal symptoms and voice characteristics in patients with gastroesophageal reflux. Acta Otolaryngologica, 121, 868–872.

Hillman, R. E., Holmberg, E. B., Perkell, J. S., Walsh, M., and Vaughan, C. (1989). Objective assessment of vocal hyperfunction: An experimental framework and initial results. Journal of Speech and Hearing Research, 32, 373–

392.

Jiang, J. J., and Titze, I. R. (1994). Measurement of vocal fold intraglottal stress and impact stress. Journal of Voice, 8, 132–144.

Koufman, J. A., Amin, M. R., and Panetti, M. (2000). Rele-vance of reflux in 113 consecutive patients with laryngeal and voice disorders. Otolaryngology–Head and Neck Sur-gery, 123, 385–388.

Murry, T., and Woodson, G. (1995). Combined-modality treatment of adductor spasmodic dysphonia with botulinum toxin and voice therapy. Journal of Voice, 6, 271–276.

Ramig, L. O., Sapir, S., Countryman, S., Pawlas, A. A., O’Brien, C., Hoehn, M., et al. (2001). Intensive voice treat-ment (LSVT) for patients with Parkinson’s disease: A 2 year follow up. Journal of Neurology, Neurosurgery, and Psychiatry, 71, 493–498.

Ramig, L. O., Sapir, S., Fox, C., and Countryman, S. (2001).

Changes in vocal loudness following intensive voice treat-ment (LSVT) in individuals with Parkinson’s disease:

A comparison with untreated patients and normal age-matched controls. Movement Disorders, 16, 79–83.

Roy, N., Gray, S. D., Simon, M., Dove, H., Corbin-Lewis, K., and Stemple, J. C. (2001). An evaluation of the e¤ects of two treatment approaches for teachers with voice disorders:

A prospective randomized clinical trial. Journal of Speech-Language-Hearing Research, 44, 286–296.

Shaw, G. Y., Searl, J. P., Young, J. L., and Miner, P. B.

(1996). Subjective, laryngoscopic, and acoustic measure-ments of laryngeal reflux before and after treatment with omeprazole. Journal of Voice, 10, 410–418.

Smith, S., and Thyme, K. (1976). Statistic research on changes in speech due to pedagogic treatment (the accent method).

Folia Phoniatrica, 28, 98–103.

Solomon, N. P., and Di Mattia, M. S. (2000). E¤ects of a vo-cally fatiguing task and systemic hydration on phonation threshold pressure. Journal of Voice, 14, 341–362.

Stemple, J. C., Lee, L., D’Amico, and Pickup, B. (1994). E‰-cacy of vocal function exercises as a method of improving voice production. Journal of Voice, 8, 271–278.

Titze, I. R. (1994). Mechanical stress in phonation. Journal of Voice, 8, 99–105.

Titze, I. R. (2002). Regulating glottal airflow in phonation:

Application of the maximum power transfer theorem to a low dimensional phonation model. Journal of the Acoustical Society of America, 111, 367–376.

Verdolini, K. (2000). Case study: Resonant voice therapy. In J. Stemple (Ed.), Voice therapy: Clinical studies (2nd ed., pp. 46–62). San Diego, CA: Singular Publishing Group.

Verdolini, K., Druker, D. G., Palmer, P. M., and Samawi, H.

(1998). Laryngeal adduction in resonant voice. Journal of Voice, 12, 315–327.

Verdolini, K., Titze, I. R., and Fennell, A. (1994). Dependence of phonatory e¤ort on hydration level. Journal of Speech and Hearing Research, 37, 1001–1007.

Verdolini-Marston, K., Burke, M. K., Lessac, A., Glaze, L., and Caldwell, E. (1995). Preliminary study of two methods of treatment for laryngeal nodules. Journal of Voice, 9, 74–85.

Verdolini-Marston, K., Sandage, M., and Titze, I. R. (1994).

E¤ect of hydration treatments on laryngeal nodules and polyps and related voice measures. Journal of Voice, 8, 30–47.

Yamaguchi, H., Yotsukura, Y., Hirosaku, S., Watanabe, Y., Hirose, H., Kobayashi, N., and Bless, D. (1993). Pushing exercise program to correct glottal incompetence. Journal of Voice, 7, 250–256.

Further Readings

Boone, D. R., McFarlane, S. C. (1994). The voice and voice therapy (5th ed.). Englewood Cli¤s, NJ: Prentice Hall.

Colton, R., and Casper, J. K. (1996). Understand voice prob-lems: A physiological perspective for diagnosis and treatment (2nd ed.). Baltimore: Williams and Wilkins.

Kotby, M. N. (1995). The Accent Method of voice therapy. San Diego, CA: Singular Publishing Group.

Stemple, J. C. (2000). Voice therapy: Clinical studies (2nd ed.).

San Diego, CA: Singular/Thompson Learning.

Stemple, J. C., Glaze, L. E., and Gerdeman, R. K. (1995).

Clinical voice pathology: Theory and management (2nd ed.).

San Diego, CA: Singular Publishing Group.

Titze, I. R. (1994). Principles of voice production. Englewood Cli¤s, NJ: Prentice Hall.

Verdolini, K., and Krebs, D. (1999). Some considerations on the science of special challenges in voice training. In G. Nair, Voice tradition and technology: A state-of-the-art studio (pp. 227–239). San Diego, CA: Singular Publishing Group.

Verdolini, K., Ostrem, J., DeVore, K., and McCoy, S. (1998).

National Center for Voice and Speech’s guide to vocology.

Iowa City, IA: National Center for Voice and Speech.

Verdolini, K., and Ramig, L. (2001). Review: Occupational risks for voice problems. Journal of Logopedics, Phoniatrics, and Vocology, 26, 37–46.

Voice Therapy for Neurological