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The Voice Clinic

last modified on: Wed, 03/27/2024 - 21:50

see also: Teaching Vocal Heath as Music Educator -- Music and Medicine on Monday


  1. The Voice Clinic is an intensive evaluation of patients with organic and/or functional voice disorders (voice problems). The goals of this program are to:
    1. Determine the cause of the voice problem and make appropriate recommendations.
    2. Establish an objective assessment of a patient's voice disorder to permit comparisons over time and to direct further therapy on an individual basis.
    3. Further general knowledge regarding voice problems by maintaining a detailed data base (see assessment for spasmodic dysphonia) of subjective and objective parameters describing a wide spectrum of voicing abnormalities.
  2. The Voice Clinic convenes daily and is available for patients with voice disorders. The assessment includes: 
    1. Medical history and physical examination
    2. Voice related history and patient ratings of vocal function:
      1. Patient's complete history intake questionnaires designed to gather information pertaining to parameters of the voice problem and its effect on social, familial, and occupational interactions
    3. Videostroboscopy and laryngeal function studies:
      1. Vocal function measurements are obtained, including average pitch, pitch range and intensity, jitter, shimmer, harmonics to noise ratio, maximum phonation time, and S/Z ratio. Voice-range profiles are performed for select patients (usually professional singers).
      2. Videostroboscopic examination is performed.
    4. Evaluation of response to therapeutic probes:
      1. When indicated, therapeutic vocal techniques are assessed while monitoring the patient's voice, body posture, and facial, oromandibular, and laryngeal movement patterns at rest and during voicing tasks.
      2. Therapeutic probes typically tested include resonant voice, yawn-sigh, pitch or loudness variation, and musculoskeletal manipulation among others.
    5. Conjoint mulidisciplinary assessment with Speech Pathology and Otolaryngology.


  1. Rationale for Evaluation
    1. The patient responds to the following:
      1. When did you first become concerned about your voice?
      2. What did you notice about your voice that concerned you?
      3. Did the problem begin suddenly or gradually?
      4. What have you done about it?
  2. Voice-related History
    1. The patient responds (yes or no) to each of the following
      1. Do you now or have you ever smoked tobacco? (If yes, how long have you smoked and how many packs per day have you smoked on average?)
      2. Do you have any allergies to environmental irritants?
      3. Do you have any history of alcohol overuse or abuse?
      4. Do you have frequent (more than twice/year) sinus infections?
      5. Do you have any problems with heartburn or do you take antacids or acid blockers?
      6. Do you do loud talking or shouting on a frequent basis? (If yes, describe.)


  1. The patient responds to each of the following:
    1. Dysphonia
    • "If your normal voice were represented by the number 0 and if the worst voice you could imagine for yourself were represented by the number 6, what number between 0 and 6 would describe your voice quality today?"
    1. Impact
    • "If the number 0 meant your voice quality as it is today was not affecting your life at all, and if the number 6 meant your voice quality was getting in the way of everything you need to do every day, what number between 0 and 6 would describe the impact your voice quality is having on your life?"
    1. Effort
    • "Do you have to work harder than normal to produce voice for speech?" If the patient responds positively, ask the following: "If the number 100 meant you could produce voice with normal speaking effort, and if the number 200 meant you had to work twice as hard as normal to produce sound for speech, and if the number 300 meant you had to work three times as hard as normal, and so on, what number would you use to describe how effortful it is to speak? You can use numbers between the hundreds if you like."


  1. Ratings of Dysphonia (GRBAS scale)
    1. Grade: The clinician rates the overall level of dysphonia where 0 = normal, 1 = mild dysphonia, 2 = moderate dysphonia, and 3 = severe dysphonia
    2. Roughness: The clinician rates the level of vocal roughness where 0 = normal, 1 = mild roughness, 2 = moderate roughness, and 3 = severe roughness
    3. Breathiness: The clinician rates the level of vocal breathiness where 0 = normal, 1 = mild breathiness, 2 = moderate breathiness, and 3 = severe breathiness
    4. Asthenia: The clinician rates the level of vocal asthenia (weakness) where 0 = normal, 1 = mild asthenia, 2 = moderate asthenia, and 3 = severe asthenia
    5. Strain: The clinician rates the level of vocal strain where 0 = normal, 1 = mild strain, 2 = moderate strain, and 3 = severe strain
  2. Ratings of Pitch
    1. Adequacy: The clinician rates habitual pitch adequacy as 1 = normal, 2 = abnormally high, and 3 = abnormally low
    2. Range: The clinician rates pitch range as 1 = normal and 2 = abnormally restricted
    3. Breaks: The clinician rates frequency pitch breaks as 1 = none, 2 = less than 1/second, and 3 = more than 1/second
  3. Ratings of Respiratory Impairment
    1. The clinician describes the patient's respiratory adequacy for voice as 1 = perceptual evidence or history of respiratory impairment and 2 = no perceptual evidence or history of respiratory impairment
  4. Useful descriptors of vocal assessment
    1. Breathy or soft: describes voice that is associated with incomplete glottic closure (eg: unilateral VC paralysis)
    2. Diplophonic or multiphonic: occurs with unequal vibratory patterns within a single vocal cord or between both cords
    3. Tight, strangled or strained: glottis is overclosed (eg dystonia; pseudobulbar palsies)
    4. Wet, gargling, hydrophonic: results of excessive mucoid secretions within the glottic space
    5. Rough: describes TVC vibration mixed with ventricular vibration


  1. Acoustic Measures
    1. Average pitch: The patient repeats the sustained vowel "ah" 3 times, each lasting at least three seconds. For these, the average pitch (in Hertz) can be measured. Adult females generally have an average pitch of 175 to 250 Hz, while male adults average 80 to 150 Hz.
    2. Jitter perturbation: From the same vowel productions used in #1 (above), the cycle-to-cycle pitch period variation can be established. This is reflective of the frequency perturbation and normally falls below 1%.
    3. Shimmer perturbation: As with jitter, shimmer is a measure of perturbation occurring in vowel production using the same sustained "ah" vowel. Shimmer reflects cycle-to-cycle amplitude variations in the voice waveform. Normal shimmer values are less than 5%.
    4. Noise-to-harmonic ratio: From the same vowels, the amount of the signal coming from voicing versus noise can be measured. Normal noise-to-harmonic ratio is less than 0.2%. Normal measures of jitter, shimmer, and noise-to-harmonic ratio are influenced by algorithm, recording environment, recording technique, and recording hardware.
    5. Maximum phonation time: The maximum amount of time a person can sustain phonation of "ah" is timed. Typically, adult females sustain phonation of "ah" from 15 to 25 seconds; while males range from 25 to 35 seconds.
    6. S/Z ratio: The patient is timed while sustaining production of "s" and "z" for as long as possible. "S" and "z" are essentially produced in the same way; however, the "z" is voiced, while the "s" is not. The ideal ratio of "1" is when the productions are sustained for the same amount of time. If there are difficulties in glottal valving, the "s" will be phonated longer and will be reflected by ratios greater than 1.
    7. Physiologic pitch range:
      1. Highest possible pitch: The patient is instructed to, "Start at a comfortable pitch and loudness, then raise your pitch gradually as high as it will go until it breaks off." The examiner demonstrates.
      2. Lowest possible pitch: The patient is instructed to, "Start at a comfortable pitch and loudness, then lower your pitch gradually as low as it will go, as if you were yawning or sighing." The examiner demonstrates.

Videostroboscopy protocol including Videostroboscopy - with audio and video


  1. Polyps Nodules Cysts
  2. Instructions to Patients about Vocal Cord Paralysis Treatment (Injection Laryngoplasty and Approaches Requiring Open Surgery) also relevant for Glottic Incompetence (Incomplete Vocal Cord Closure)
  3. Instructions to patients about vocal process granuloma (contact granuloma of the vocal cords)
  4. Slide 06b Common Voice Disorders Acute Viral Laryngitis
  5. Vocal Tremor Response to Botox (Sequence of Videos) - Case Example
  6. Slide 09 Common Voice Disorders Muscle Tension Dysphonia

Endoportal access (password protected)


Baken RJ. Clinical measurement of speech and voice. Boston, Mass: College-Hill Press; 1987.

Colton RH, Casper JK. Understanding Voice Problems: A Physiological Perspective for Diagnosis and Treatment. Baltimore, Md: Williams & Wilkins; 1990;165-210:309-316.

Eckel FC, Boone DR. The s/z ratio as an indicator of laryngeal pathology. J Speech Hear Dis. 1983;46:147-149.

Multidimensional Voice Program. [Software]. Lincoln Park, NJ: Kay Elemetrics; 1999.

Verdolini K. Guide to Vocology. Iowa City, Ia: National Center for Voice and Speech; 1998.

Weinberg B. Diagnosis of phonatory based voice disorders. In: Diagnosis in Speech-Language Pathology. Meitus IJ, Weinberg B, eds. Baltimore, MD: University Park Press; 1983: 151-182.