Assessment:
A Speech Language Pathologist should not treat a voice disorder without first having the patient undergo a medical evaluation by an ENT, Otolaryngologist, or other physician.
SLPs do not treat medical conditions, such as nodules (Boone, 2010).
SLPs treat voice issues associated with medical conditions affecting:
Vocal Nodule Assessments:
3 Main Types:
Laryngoscopic/ Endoscopy Examination:
Endoscopy:
Endoscopy and Mirror Laryngoscopy:
Mirror Exam:
Rigid Laryngoscope
Flexible Laryngoscope
Microlaryngoscopy/ Direct Laryngoscopy
Video Stroboscopy
A specialized diagnostic procedure in which a stroboscopic light is used in conjunction with a laryngoscope to electronically slow down the motion of the vocal folds in order to identify subtle changes in vibratory patterns that are diagnostically significant.
Video stroboscopy is used to differentiate vocal fold nodules from vocal fold polyps and cysts.
(Ricter, 2011) (Williamson,2008)
*Advantages of Stroboscopy:
Perceptual Evaluation:
In a perceptual evaluation the SLP listens to the patient’s voice during a reading or conversational task. The patient’s voice is then rated, on a scale of 0=normal to 4=severely deviant, in the areas of pitch, loudness, voice quality, resonance, articulation, intelligibility, respiration, prosody, and other. There are subcategories located beneath each section. Pluses and minuses are given to indicate high (+) or low (-) values. For example, a ranking of +1 on pitch would equal a high pitch that was mildly deviant. The trouble with the perceptual evaluation is that it is dependent on the experience of the listener. The evaluation may vary from examiner to examiner (Boone, 2010).
Instrumental Assessment:
Instrumental evaluation uses computer software such as Speech Analyzer 3.1 or other instrumentation to measure characteristics of a patient’s voice. Each characteristic is calculated for 4 different vocal tasks. It supplements the perceptual evaluation with quantifiable data. However, instrumental assessment is more time consuming than performing perceptual evaluation, and unless a free download such as Speech Analyzer 3.1 is being used, it can be very costly (Boone, 2010).
Electromyography (EMG)
When a muscle contracts a small electrical current is produced which is typically proportional to the strength of the muscle activity. EMG measures this electrical activity of muscles. There are two types. Surface EMG involves placing two electrodes on the skin overlying the muscles to be investigated. Intramuscular EMG involves inserting a small needle electrode into the muscle itself. In both instances, the electrical activity is typically displayed on an oscilloscope. This technique has limited application but does assist in detecting levels of laryngeal muscle tension and may be used in cases of identified vocal fold paralysis. EMG is typically carried out by trained physiologists or physicians (Williamson,2008).
Electroglottograph (EGG)
This is a non-invasive device that measures the contact between the vocal folds. Two electrodes are placed either side of the larynx and a small electrical current is passed between them. As the vocal folds open (abduct) and close (adduct), the resistance to the flow of the current alters. The variations in resistance are displayed as an image on a computer screen which represents the movement/contacts of the vocal folds. This technique is also useful in gathering information about the fundamental frequency of the voice, and the voice quality. Unlike vocal tract imaging and EMG techniques, electroglottography is commonly carried out by speech therapists (Williamson,2008).
Praat
Written by Paul Boersma and David Weenink at the University of Amsterdam, Praat is a computer program with which you can analyze, synthesize, and manipulate speech. It also has an in-built Voice Report tool. It is available for many different computer operating systems and can be downloaded for free from http://www.praat.org/.
(Williamson,2008).
Other Speech Analysis Software:
Instrumental vs. Perceptual Evaluation:
SLPs do not treat medical conditions, such as nodules (Boone, 2010).
SLPs treat voice issues associated with medical conditions affecting:
- Respiration à Respiratory Support/ volume control
- Phonation à Dysphonia
- Resonance à Resonance
- In some cases Prosody
- Nodules may be treated medically, surgically, and/or behaviorally.
- Surgical intervention involves removing the nodule from the vocal cord.
- This approach only occurs when the nodules are very large or have existed for a long time.
- Surgery is rare for children.
- Medical problems may be treated to reduce their impact on the vocal cords.
- This includes treatment for gastroesophageal reflux disease (GERD), allergies, and thyroid problems.
- Medical intervention to stop smoking or to control stress is sometimes needed.
- Many people receive behavioral intervention, or voice therapy, from an SLP.
- Voice therapy involves teaching good vocal hygiene, reducing/stopping vocal abusive behaviors, and direct voice treatment to alter pitch, loudness, or breath support for good voicing.
- Stress reduction techniques and relaxation exercises are often taught as well. (ASHA, 2009)
Vocal Nodule Assessments:
3 Main Types:
- Laryngoscopic/ Endoscopy Examination
- Perceptual
- Instrumental
Laryngoscopic/ Endoscopy Examination:
Endoscopy:
- Used to study vocal tract anatomy and physiology, e.g., mucosal wave
- Oral Scope - solid/rigid glass rod --> excellent picture
- Nasal Scope - flexible fiberoptic cable used to view connected speech
- Stroboscope - flashing light source --> slow motion-like observation of vocal pathology
Endoscopy and Mirror Laryngoscopy:
- Used by both Laryngologist and SLP
- Laryngologist - assesses laryngeal disease
- SLP - assesses laryngeal function related to clinical stimulation
Mirror Exam:
- The indirect mirror exam is the initial procedure used to view the larynx. It is quick, inexpensive, and only requires a mirror and external light source.
- A small mirror on a handle is placed against the client’s soft palate angled so that the vocal folds can be seen from above. They can be viewed when at rest and when moving - the person is asked to produce a continuous vowel sound: /i/.
- Gross abnormalities may be detected quickly, but subtle abnormalities may be missed.
- Disadvantages include:
- the larynx not being in physiologic phonation position (the tongue is extended and the larynx is elevated),
- some anatomic features limit the exam
- hyper-reflexive gag is present in 5-10% of patients.
Rigid Laryngoscope
- This is similar to mirror laryngoscopy in that the instrument is also placed into the client’s mouth towards the back of the throat. In this case, however, the handle incorporates an angled lens which sends images of the vocal folds to a camera.
- Rigid laryngeal endoscopy is performed in the office using 70 or 90 degree telescopes passed through the mouth to obtain images of the larynx and pharynx.
- These are the highest quality images obtainable and offer excellent magnification.
- The patients are viewed in a nonphysiologic phonation position similar to the indirect examination.
- Anatomic factors and hyper-reflexive gags can again limit the results.
Flexible Laryngoscope
- The flexible laryngoscope is probably the tool that most otolaryngologists rely upon in the evaluation of the dysphonic patient.
- A narrow, flexible, fiber optic cable with a camera attached is inserted through the nose to a position at the back of the throat just above the vocal folds. Unlike mirror and rigid techniques, because there is no instrument in the mouth, the vocal folds can be observed at rest, when phonating vowels and now during normal speaking.
- It is the sole method that allows examination of the nasopharynx, palate, larynx, and pharynx in a near physiologic position.
- It can be performed relatively easily even in patients with hyper-responsive gags and pediatric patients.
Microlaryngoscopy/ Direct Laryngoscopy
- A procedure conducted under general anesthesia, which allows the physician to examine the vocal folds of the larynx with magnification tools
- Because the client is unconscious the clinician cannot examine vocal fold movement during phonation of vowels, speaking or singing.
- If necessary, images could be taken/saved by placing a suitable camera onto the examining microscope.
- Microsurgical and laser removal of lesions is done at this time.
Video Stroboscopy
A specialized diagnostic procedure in which a stroboscopic light is used in conjunction with a laryngoscope to electronically slow down the motion of the vocal folds in order to identify subtle changes in vibratory patterns that are diagnostically significant.
Video stroboscopy is used to differentiate vocal fold nodules from vocal fold polyps and cysts.
(Ricter, 2011) (Williamson,2008)
*Advantages of Stroboscopy:
- Permanent record
- Studies laryngeal function during typical and clinically manipulated production
- Aids in pt counseling
- Aids in compliance with therapy tasks
- Share pictures with referral source
- Compare pre and post tx
- Frame-by-frame analysis of abnormal physiology/mucosal wave
- Treatment, research, and teaching
Perceptual Evaluation:
In a perceptual evaluation the SLP listens to the patient’s voice during a reading or conversational task. The patient’s voice is then rated, on a scale of 0=normal to 4=severely deviant, in the areas of pitch, loudness, voice quality, resonance, articulation, intelligibility, respiration, prosody, and other. There are subcategories located beneath each section. Pluses and minuses are given to indicate high (+) or low (-) values. For example, a ranking of +1 on pitch would equal a high pitch that was mildly deviant. The trouble with the perceptual evaluation is that it is dependent on the experience of the listener. The evaluation may vary from examiner to examiner (Boone, 2010).
Instrumental Assessment:
Instrumental evaluation uses computer software such as Speech Analyzer 3.1 or other instrumentation to measure characteristics of a patient’s voice. Each characteristic is calculated for 4 different vocal tasks. It supplements the perceptual evaluation with quantifiable data. However, instrumental assessment is more time consuming than performing perceptual evaluation, and unless a free download such as Speech Analyzer 3.1 is being used, it can be very costly (Boone, 2010).
Electromyography (EMG)
When a muscle contracts a small electrical current is produced which is typically proportional to the strength of the muscle activity. EMG measures this electrical activity of muscles. There are two types. Surface EMG involves placing two electrodes on the skin overlying the muscles to be investigated. Intramuscular EMG involves inserting a small needle electrode into the muscle itself. In both instances, the electrical activity is typically displayed on an oscilloscope. This technique has limited application but does assist in detecting levels of laryngeal muscle tension and may be used in cases of identified vocal fold paralysis. EMG is typically carried out by trained physiologists or physicians (Williamson,2008).
Electroglottograph (EGG)
This is a non-invasive device that measures the contact between the vocal folds. Two electrodes are placed either side of the larynx and a small electrical current is passed between them. As the vocal folds open (abduct) and close (adduct), the resistance to the flow of the current alters. The variations in resistance are displayed as an image on a computer screen which represents the movement/contacts of the vocal folds. This technique is also useful in gathering information about the fundamental frequency of the voice, and the voice quality. Unlike vocal tract imaging and EMG techniques, electroglottography is commonly carried out by speech therapists (Williamson,2008).
Praat
Written by Paul Boersma and David Weenink at the University of Amsterdam, Praat is a computer program with which you can analyze, synthesize, and manipulate speech. It also has an in-built Voice Report tool. It is available for many different computer operating systems and can be downloaded for free from http://www.praat.org/.
(Williamson,2008).
Other Speech Analysis Software:
- WASP
- SIL Speech Analyzer- A free download is available online. This software is fairly easy to use but does not provide measures of jitter and shimmer.
- SFS.
- CoolEdit
- WaveSurfer
Instrumental vs. Perceptual Evaluation:
- Good evaluation can be done with or without instrumentation
- Instrumentation documents and quantifies data, but will not make up for weak powers of observation, modest clinical skills, or lack of knowledge
- Crucial factor is the ability to listen critically, and think objectively