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Voice Disorders

See the Assessment section of the Voice Disorders evidence map for pertinent scientific evidence, expert opinion, and client/caregiver perspective. 


Screening may be conducted if a voice disorder is suspected. It may be triggered by concerns from individuals, parents, teachers, or health care providers. When deviations from normal voice are detected during screening, further evaluation is warranted.

Screening includes evaluation of vocal characteristics related to respiration, phonation, and resonance, as well as vocal range and flexibility (e.g., pitch, loudness, pitch range, and endurance). Clinicians may use a formal screening tool (Lee et al., 2004) or obtain data using informal tasks. Standardized self-report questionnaires can be included for a more thorough screening (e.g., Deary, Wilson, Carding, & MacKenzie, 2003; Hogikyan & Sethuraman, 1999; Jacobson et al., 1997).

Comprehensive Assessment

Assessment and treatment of voice disorders may require use of appropriate personal protective equipment.

All patients/clients with voice disorders are examined by a physician, preferably in a discipline appropriate to the presenting complaint. The physician's examination may occur before or after the voice evaluation by the speech-language pathologist.

A comprehensive assessment is conducted for individuals suspected of having a voice disorder, using both standardized and nonstandardized measures (see ASHA resource on assessment tools, techniques, and data sources). Norms are based on age, gender, type of instrumentation used, cultural background, and dialect. For a review of clinical voice assessments, see Roy et al. (2013).

Diagnostic therapy may be performed as part of the comprehensive assessment to help in making a diagnosis and to determine if the individual is stimulable to voice therapy efforts.

Consistent with the World Health Organization's (WHO) International Classification of Functioning, Disability and Health (ICF) framework (ASHA, 2016b; WHO, 2001), comprehensive assessment is conducted to identify and describe

  • impairments in body structure and function, including underlying strengths and weaknesses in speech sound production and verbal/nonverbal communication;
  • co-morbid deficits such as other health conditions and medications that can affect voice;
  • the individual's limitations in activity and participation, including functional status in communication and interpersonal interactions;
  • contextual (environmental and personal) factors that serve as barriers to, or facilitators of, successful communication and life participation; and
  • the impact of communication impairments on quality of life and functional limitations relative to premorbid social roles and abilities for the individual and the impact on his or her community.

See the ASHA resource titled Person-Centered Focus on Function: Voice [PDF] for an example of assessment data consistent with ICF.

Comprehensive Assessment for Voice Disorders: Typical Components

Case History
  • Individual's description of voice problem, including onset and variability of symptoms
  • Medical status and history, including surgeries, chronic disorders, and medications
  • Previous voice treatment
  • Daily habits related to vocal hygiene
  • Individual's assessment of how voice problem affects
    • emotions and self-image; and
    • ability to communicate effectively in everyday activities and in social and work settings (e.g., Hogikyan & Sethuraman, 1999; Jacobson et al., 1997; Ma & Yiu, 2001).
Oral-Peripheral Examination
  • Assessment of structural or motor-based deficits that may affect communication and voice, including strength, speed, and range of motion of oral musculature
  • Assessment of symmetry and movement of structures of the face, oral cavity, head, neck, and respiratory system during rest and purposeful speech tasks
  • Testing of mechano-sensation of face and oral cavity
  • Testing of chemo-sensation (i.e., taste and smell)
  • Assessment of laryngeal sensations (dryness, tickling, burning, pain, etc.) and palpation of extrinsic laryngeal musculature, as indicated
Assessment of Respiration
  • Respiratory pattern (abdominal, thoracic, clavicular)
  • Coordination of respiration with phonation (breath-holding patterns, habitual use of residual air, length of breath groups)
  • Maximum phonation time (MPT; Dejonckere, 2010; Speyer et al., 2010)
  • s/z ratio to assess for glottal insufficiency, which may be indicative of laryngeal pathology (Eckel & Boone, 1981; Stemple et al., 2010)

Auditory-Perceptual Assessment

Subjective Assessment Based on Clinical Impressions of the SLP

Voice Quality

  • Consensus features assessed during production of sustained vowels, sentences, and running speech
    • Roughness—perceived irregularity in voicing source
    • Breathiness—audible air escape in voice
    • Strain—perception of excessive vocal effort
    • Pitch (perceptual correlate of fundamental frequency)—deviations from normal relative to age, gender, and referent culture
    • Loudness (perceptual correlate of sound intensity)—deviations from normal relative to age, gender, and referent culture
    • Overall severity—global, integrated impression of voice deviance
  • Additional perceptual features
    • Diplophonia, aphonia, pitch instability, tremor, vocal fry, falsetto, wet/gurgly

(Kemper, Gerratt, Abbott, Barkmeier-Kraemer, & Hillman, 2009; ASHA, 2002; ASHA , n.d.)


  • Assess resonance quality (normal, hyponasal, hypernasal, cul-de-sac).
  • If abnormal, assess stimulability for normal resonance.
  • If normal, evaluate the focus of resonance (oral, pharyngeal/laryngeal, nasal).

See ASHA's Practice Portal page on Resonance Disorders


  • Voice onset/offset (e.g., delayed voice onset; quality of voice at onset)
  • Ability to sustain the voice to achieve appropriate phrasing during speaking
  • Ability to demonstrate strong and consistent rate of vocal fold valving during diadochokinesis


Deviations from normal relative to age, gender, and referent culture

Instrumental Assessment

Adapted from Recommended Protocols for Instrumental Assessment of Voice (ASHA, 2015)

Laryngeal Imaging

  • Measures of structure and gross function (using videoendoscopy) and measures of vocal fold vibration during phonation (using videostroboscopy)
    • Videolaryngoendoscopy
      • Vocal fold edges—appearance of superior vocal fold edges during abduction
      • Vocal fold mobility—movement of vocal folds toward and away from midline at level of cricoarytenoid joint during laryngeal diadochokinetic task
      • Supraglottic activity—degree of compression of supraglottic structures during sustained phonation
    • Videolaryngostroboscopy
      • Regularity—consistency of successive glottic cycles
      • Amplitude—lateral movement of the vocal fold medial plane
      • Mucosal wave—independent lateral movement of mucosa over vocal fold
      • Left/right phase symmetry—symmetry of vocal folds (opening, closing, maximum lateral–medial excursion) during glottic cycle
      • Vertical level—level difference in vertical plane between vocal folds during maximum closed phase of glottic cycle
      • Glottal closure pattern—glottal configuration during maximum closure
      • Glottal closure duration—relative proportion of glottal cycle in which glottis is closed

Acoustic Assessment

  • Objective measures of vocal function related to vocal loudness, pitch, and quality
    • Vocal amplitude
      • Habitual sound pressure level (SPL) in decibels (dB)—typical sound level of voice during connected speech (standard reading passage)
      • Minimum and maximum vocal SPL (dB)—softest and loudest sustainable phonation
    • Vocal frequency
      • Mean vocal f0 (Hz)—average of the estimates of the f0 for acoustic signal recorded during connected speech (standard reading passage)
      • Vocal f0 standard deviation (SD; Hz)—SD of the estimates of the f0 for acoustic signal recorded during connected speech
      • Minimum and maximum vocal f0 (Hz)—f0 values for the lowest and highest pitched sustainable phonations
    • Vocal signal quality
      • Vocal cepstral peak prominence (CPP; dB)—relative amplitude of the peak in the cepstrum that represents the dominant rahmonic of the vocal acoustic signal (sustained vowels and connected speech samples)

Aerodynamic Assessment

  • Measures (using noninvasive procedures) of glottal aerodynamic parameters required for phonation
    • Glottal airflow
      • Average glottal airflow rate (L/sec or mL/sec)—estimated from oral airflow rate during vowel production
    • Subglottal air pressure
      • Average subglottal air pressure (cm of water [cmH2O] or kilopascals [kPa])—estimated for intraoral air pressure produced during repetition of stop consonants in syllable strings
    • Mean vocal SPL and f0—extracted from simultaneously recorded acoustic signal; facilitates interpretation of airflow and air pressure measurements

Assessment may result in

  • diagnosis of a voice disorder;
  • clinical description of the characteristics and severity of the disorder;
  • statement of prognosis and recommendations for intervention;
  • identification of appropriate treatment or management options; and
  • referral to other professionals, as needed.

Content Disclaimer: The Practice Portal, ASHA policy documents, and guidelines contain information for use in all settings; however, members must consider all applicable local, state and federal requirements when applying the information in their specific work setting.