Resonance Disorders

The scope of this page is resonance disorders in children and adults. Resonance disorders—specifically hypernasality—are also discussed in ASHA’s Practice Portal page on Cleft Lip and Palate as they relate to clefting.

Velopharyngeal dysfunction (VPD) is discussed in this page as it relates to resonance disorders. See Possible Causes of Hypernasality and/or Nasal Emission. For a discussion of articulation disorders that may co-occur with VPD and resonance disorders, see ASHA’s Practice Portal page on Cleft Lip and Palate.

Resonance disorders are not voice disorders, although they are often mislabeled as such. Resonance disorders should not be confused with conditions targeted by resonant voice therapy, an approach that emphasizes phonation with the least effort and impact on the vocal folds. See ASHA’s Practice Portal page on Voice Disorders. Resonance, however, depends upon voicing as discussed below.

See the Velopharyngeal Dysfunction Evidence Map for summaries of available research on this topic as it relates to resonance disorders.

Resonance is the modification of sound from the vocal folds and is determined by the size and shape of the vocal tract, including the pharyngeal, oral, and nasal cavities.

Speech resonance is the result of the transfer of sound produced by the vocal folds (source) through the vocal tract (filter). The vocal tract selectively enhances harmonics of the source (voicing) based on the size and/or shape of the supralaryngeal cavities, the pharynx, and the oral and nasal cavities.

The velopharyngeal valve is integral to achieving appropriate speech resonance; however, other aspects of the vocal tract also contribute to perceived resonance. These include

  • the size and shape of the resonating cavities (pharynx, oral cavity, and nasal cavity);
  • the position of the tongue; and
  • the degree of mouth opening and lip rounding.

Normal resonance is achieved through an appropriate balance of oral and nasal sound energy, based on the intended speech sound. Resonance varies for vowels, voiced oral consonants, and nasal consonants as well as across languages and dialects. Most vowels and vocalic consonants in the English language are predominantly oral, meaning they are produced with the velopharyngeal port closed or nearly closed. Normal resonance has a range of acceptability and is perceived along a continuum (Peterson-Falzone et al., 2010).

Resonance disorders result from too much or too little nasal and/or oral sound energy in the speech signal. They can result from structural or functional (e.g., neurogenic) causes. Speech-language pathologists (SLPs) use differential diagnosis to determine if issues are related to structural and/or functional causes or if the errors are due to mislearning as the different etiologies require different treatment plans. Articulation errors due to mislearning may be misinterpreted as a resonance disorder.

Resonance disorders should not be confused with nasal airflow errors or distortions. Nasal airflow errors are related to articulation when there is an inappropriate escape or release of air through the nasal cavity during production of pressure consonants—consonants that are produced by bursts of streamed air (i.e., /p, b, t, d, k, g, f, v, s, z, ʃ, t͡ʃ, θ, d͡ʒ, ʒ, ð/). Nasal airflow errors may be categorized into one of the following error types:

  • learned errors—maladaptive articulation errors that are produced through the nose and used to replace oral fricatives (e.g., nasal fricatives, pharyngeal fricatives, and phoneme-specific nasal emission)
  • obligatory errors—exist due to structural abnormalities that result in velopharyngeal insufficiency and oral structural deviations (e.g., oronasal fistulas, dental deviations, or malocclusions)
  • compensatory errors—actively learned maladaptive articulations that develop in response to abnormal structures found in VPD

See ASHA’s Practice Portal page on Cleft Lip and Palate for further discussion.

Resonance disorders include the following:

  • Hypernasality—occurs when there is abnormal sound energy in the nasal cavity during production of voiced, oral sounds. Hypernasality is primarily a vowel phenomenon but can occur on other voiced sounds.
  • Hyponasality—occurs when there is reduced nasal resonance or energy associated with nasal sounds, typically due to a blockage or an obstruction in the nasopharynx or nasal cavity or related to a neurological condition.
  • Cul-de-sac resonance—occurs when sound circulates within a cavity (oral, nasal, or pharyngeal) being “trapped” and unable to exit, typically because of an obstruction within the vocal tract. As described below, different types of cul-de-sac resonance are possible depending on the location of the obstruction.
  • Mixed resonance—presence of hypernasal, hyponasal, and/or cul-de-sac resonance in the same speaker depending on the intended speech sound.

Hypernasality should not be confused with nasal air emission. Although some clinicians may use these terms interchangeably, they are distinct symptoms of VPD that typically occur on different speech sounds. Hypernasality is a resonance phenomenon that occurs primarily on vowels, and nasal air emission is an aerodynamic phenomenon that occurs primarily on oral pressure consonants, especially voiceless consonants (Zajac & Vallino, 2016). When VPD is present, both hypernasality and nasal air emission can occur in the same speaker, but they are different entities.

See ASHA’s Practice Portal page on Cleft Lip and Palate for further discussion of nasal air emission, including learned nasal fricatives.

Incidence is the number of new cases of a disorder or condition identified in a specific time period. Prevalence is the number of individuals who are living with the disorder or condition in a given time period.

Given the various etiologies and presentations of resonance disorders, overall incidence and prevalence are unknown. Incidence and prevalence estimates for one cause of resonance disorders—velopharyngeal dysfunction (VPD)—are reported in the literature for the following disorders and conditions.

References below are made to both velopharyngeal insufficiency (VPI) and VPD. VPI refers to structural deficits, and VPD refers to dysfunction that may or may not include structural elements.

Cleft palate, including submucous cleft palate, is the condition most commonly associated with VPD and hypernasality (Kummer et al., 2015; Peterson-Falzone et al., 2010; Zajac & Vallino, 2016). For individuals with nonsyndromic cleft palate following primary palatal surgery, 28.8% exhibited significant hypernasality (Ha et al., 2015). The prevalence of VPI based on the rate of secondary surgery was 8.1%–23.81% (Goudy et al., 2011; Ha et al., 2015; O. Jackson et al., 2013). After secondary management, the rate of persisting hypernasality was 18.2% (Goudy et al., 2011).

  • Submucous cleft palate may present with VPI, hypernasal speech, or weak pressure consonants. One study found hypernasal speech in 51% of the cohort, with 10% exhibiting mild hypernasality, 19% exhibiting moderate hypernasality, and 22% exhibiting severe hypernasality. Weak pressure consonants were seen in 28.9% (Reiter et al., 2011). Velopharyngeal surgery for VPI was required in 5.5%–16.7% of individuals (Basta et al., 2014; Reiter et al., 2011). Following surgical intervention, 11%–16.1% continue to exhibit residual VPI (Isotalo et al., 2007; Nasser et al., 2008).
  • Cleft lip only was associated with hypernasal or mixed resonance in 3.2% of children with no visible palatal anomaly (Vallino et al., 2008).
  • Pierre Robin sequence typically presents with a wide U-shaped cleft palate, among other aerodigestive tract abnormalities. Resonance disorders are common, with secondary VPI surgery performed in 13.6%–33.3% of individuals (Basta et al., 2014; Filip et al., 2015; Goudy et al., 2011); however, evidence is mixed as to whether individuals with Pierre Robin sequence experience different rates of postsurgical VPI than do individuals with cleft palate alone (Filip et al., 2015; Goudy et al., 2011; Kocaaslan et al., 2020). Persisting hypernasality following secondary management was 16.3% (Goudy et al., 2011).

Genetic syndromes are often associated with resonance disorders, but the extent of the relationship is difficult to determine given frequently co-occurring voice, cognitive, and/or hearing loss (van Borsel, 2004).

  • 2 deletion syndrome (also known as velocardiofacial syndrome, DiGeorge syndrome, Shprintzen syndrome, and Sedláčková syndrome) is the most common genetic cause of congenital VPD (Kirschner, 2005). VPD was found in 55.2% of individuals with 22q11.2 deletion syndrome, occurring in 33.3% in the absence of palatal clefting (O. Jackson et al., 2019). Secondary VPI surgery was required for 17%–31.6% (Basta et al., 2014; Spruijt et al., 2012).
  • Treacher Collins syndrome may present with VPD. In one study, 28.6% of individuals required secondary surgery due to structural VPD, whereas 85.7% presented with articulatory VPD (Golinko et al., 2016).
  • Stickler syndrome may present with VPI, with 15.6% of individuals requiring secondary surgical management (Basta et al., 2014).

Other conditions or procedures associated with resonance disorders

  • Adenoidectomy had a 3.2% risk of VPI 3 weeks postoperatively, tonsillectomy had a 2.2% risk, and adenotonsillectomy had a 13.6% risk for children without cleft palate (Khami et al., 2015). In one study of children with Prader-Willi syndrome after adenotonsillectomy, 27.2% required secondary VPI surgery due to hypernasality (Crockett, Ahmed, et al., 2014).
  • Uvulopalatopharyngoplasty, a common procedure for the correction of obstructive sleep apnea, is associated with VPI as a long-term complication in 9.1% of individuals (Tang et al., 2017).
  • Hearing loss may be associated with hypernasality, hyponasality, cul-de-sac resonance, or mixed resonance. Children with cochlear implants may have less disordered resonance than those with hearing aids. One study of children with hearing aids and hearing loss at a threshold less than 70 dB HL showed 30% exhibited mild resonance impairment, 20% exhibited moderate impairment, and 10% exhibited severe impairment. Of the children with hearing aids and hearing loss at a threshold greater than 70 dB HL, 14.3% showed mildly impaired resonance, 35.7% showed moderately impaired resonance, and 42.8% showed severely impaired resonance. Among children who use cochlear implants, 47.2% exhibited mild resonance impairment, 11.1% exhibited moderate resonance impairment, and 11.1% exhibited severe resonance impairment (Baudonck et al., 2015). Another study of children with profound hearing loss found a 65.54% mean nasalance score for those who used hearing aids and a 45% nasalance score for those who used cochlear implants (Sebastian et al., 2015).
  • Huntington’s disease was associated with intermittent hypernasality in 78% of individuals from one study (Novotný et al., 2016).
  • Tumor requiring resection of the soft palate led to mild hypernasality in 43.5% and moderate–severe hypernasality in 21.7% (Barata et al., 2013).

Signs and symptoms of resonance disorders can vary depending on a number of factors, including the type of resonance disorder and the severity of the condition causing the disorder. Signs and symptoms associated with each type of resonance disorder are listed below.


  • Perceived when there is excessive nasal resonance, typically on vowels; glides; liquids; and, in severe cases, voiced oral consonants (e.g., /b/, /d/, and /g/).
  • High vowels (/u, i/) are most susceptible to effects of hypernasality and are often the first vowels in which the listener notices its presence.
  • SLPs should use differential diagnosis when working with people with velopharyngeal dysfunction with repaired cleft palate to discriminate between errors due to anatomy and errors due to mislearning.

See ASHA’s Practice Portal page on Cleft Lip and Palate for further discussion of differential diagnosis of obligatory versus learned behaviors.


  • Perceived when there is reduced nasal resonance on vowels, sonorants, and nasal consonants.
  • In more severe cases, hyponasality co-occurs with denasalization of nasal consonants (/m/, /n/, and /ŋ/), making them sound more oral in quality (e.g., /b/ for /m/, /d/ for /n/, and /g/ for /ŋ/).

Cul-de-Sac Resonance

  • Sound resonates in one of the cavities of the vocal tract (e.g., nasal, oral, or pharyngeal cavity) but is blocked at the cavity exit typically due to an obstruction (e.g., enlarged tonsils or adenoids).
  • Both oral and pharyngeal cul-de-sac resonance cause consonants to be “muffled” and indistinct and the volume of speech to be reduced.
  • Nasal cul-de-sac resonance causes a “tinny” resonance and indistinct speech.

Mixed Resonance

  • Co-occurrence of hypernasality, hyponasality, and/or cul-de-sac resonance in the same speaker.
  • Hypernasality and hyponasality can occur at different times during connected speech (e.g., with apraxia).
  • Hypernasality and hyponasality may co-occur when velopharyngeal dysfunction and any form of nasopharyngeal obstruction are present.

There are several causes of resonance disorders, including velopharyngeal dysfunction (VPD), oronasal fistulas, obstruction in the nasal or pharyngeal cavity, and hearing loss. Specific causes are grouped below by type of resonance disorder.


Also see Possible Causes of Hypernasality and/or Nasal Emission.


  • Structural causes resulting in velopharyngeal insufficiency. These causes include overt, submucous, or occult submucous cleft palate; irregular adenoids or adenoid atrophy (usually in those just acquiring velo-adenoidal closure); post-adenoidectomy or enlarged tonsils that intrude into the pharynx and prevent velopharyngeal (VP) closure; post-tonsillectomy (rare but may occur due to scar tissue affecting lateral wall movement); maxillary advancement; deep pharynx (palatopharyngeal disproportion); velar hypoplasia or dysplasia; tissue deficit from tumor resection; and shrinkage following radiation therapy.
  • Structural anomalies associated with genetic syndromes resulting in hypernasality. These syndromes include 2 deletion syndrome (also known as velocardiofacial syndrome, DiGeorge syndrome, Shprintzen syndrome, and Sedláčková syndrome), CHARGE syndrome, Treacher Collins syndrome, Nager syndrome, branchio-oto-renal syndrome, Turner syndrome, Beckwith-Wiedemann syndrome, Stickler syndrome, Kabuki syndrome, Opitz G/BBB syndrome, Jacobsen syndrome, and any syndromic form of Robin sequence (Kummer, 2014; Shprintzen, 1997, 2000; Ysunza et al., 2013).
  • Neurogenic causes resulting in VP incompetency. These causes include traumatic brain injury; stroke; cerebral palsy; apraxia (congenital or acquired); velar paresis/paralysis (e.g., cranial nerve defects); neuromuscular disease (e.g., myasthenia gravis and muscular dystrophy); neurofibromatosis; and neurodevelopmental syndromes such as velocardiofacial syndrome, Prader-Willi syndrome, myotonic dystrophy, and nemaline myopathy (Shprintzen, 1997). Neurogenic causes are often associated with dysarthria and hypotonia. However, VPD “is frequently, but not universally, associated with dysarthria” (Yorkston et al., 2010, p. 203). Similarly, apraxia may or may not present with resonance issues. When hypernasality is present, it is typically related to velar weakness or discoordination of VP valving.
  • VP mislearning
    • Learned compensatory misarticulations (e.g., glottal stops and pharyngeal fricatives, nasal fricatives, tongue clicks) that develop due to the inability to generate adequate intraoral airflow for consonant production. These productions almost always persist after successful physical management of the VP mechanism because they are due to mislearning, not structural abnormalities, and require speech therapy to correct. When these errors are present, the adjacent vowels may become nasalized due to coarticulatory effects, thus leading the listener to perceive hypernasality.
    • Lack of auditory feedback in individuals who are deaf or hard of hearing. Abnormal resonance is due to limitations hearing nasal and oral contrasts because of reduced auditory feedback.

Oronasal fistula (e.g., in individuals with a history of cleft palate, trauma to the oral cavity, or ablative surgery in the oral cavity)

  • May result in hypernasality only if the fistula is large—small fistulas may cause nasal emission on anterior sounds but not necessarily hypernasality; some fistulas are asymptomatic.


  • Nasal cavity/nasopharynx obstruction (e.g., enlarged adenoids, restricted pharyngeal cavity space due to maxillary retrusion and other craniofacial anomalies).
  • Apert syndrome, and other conditions associated with upper airway obstruction, may present with hyponasality (Kummer, 2014).
  • Swelling (with or without nasal congestion) due to allergic rhinitis, common cold, adenoid hypertrophy, nasopharyngeal polyps, and hypertrophic tonsils.
  • Deviated septum (nasal septum is significantly “off-center”).
  • Choanal atresia (abnormal narrowing of the passageway from the nose to the pharynx).
  • Stenotic nares (narrow nostrils, often seen in patients with cleft lip repair).
  • Unwanted complications of corrective surgery for VPD.
  • Problems with motor planning/execution (apraxia) that result in inconsistent, abnormal VP closure on nasal phonemes.
  • Lack of auditory feedback in individuals who are deaf or have significant hearing loss may result in perceived hyponasality due to atypical tongue position during speech.

Hyponasality and/or mixed resonance is common in individuals with repaired cleft palate, especially those who also have clefts of the lip and alveolar ridge (i.e., primary palate). This is due to the frequent occurrence of either large adenoids and/or anterior nasal cavity anomalies including hypertrophic turbinates and deviated septum that reduce normal nasal resonance for nasal consonants.

Cul-de-Sac Resonance

  • Oral—microstomia (small mouth opening).
  • Nasal—blockage in the anterior part of the nose (e.g., stenotic nares, nasal polyps, or deviated septum).
  • Pharyngeal (most common)—large tonsils/enlarged adenoids. Lack of auditory feedback in individuals who are deaf or have significant hearing loss may result in cul-de-sac resonance due to atypical tongue position during speech.

Mixed Resonance

  • Problems with motor planning/execution (apraxia) that result in inconsistent, abnormal VP opening and closing.
  • Combination of VPD and any form of nasopharyngeal obstruction—hypernasality and hyponasality may co-occur; nasal resistance does not eliminate nasal resonance completely but prevents nasal consonants from maintaining their integrity (Peterson-Falzone et al., 2010).
  • Lack of auditory feedback in individuals who are deaf or have significant hearing loss may result in mixed resonance.

SLPs play a central role in the screening, assessment, diagnosis, and treatment of individuals with resonance disorders. The professional roles and activities in speech-language pathology include clinical/educational services (diagnosis, assessment, planning, and treatment); prevention and advocacy; and education, administration, and research. See ASHA’s Scope of Practice in Speech-Language Pathology (ASHA, 2016).

See ASHA’s Practice Portal page on Cleft Lip and Palate for further information regarding the role of the SLP in the management of individuals with cleft lip and palate and associated craniofacial conditions, including velopharyngeal dysfunction.

In cases of resonance disorders in other (noncleft) populations, appropriate roles for SLPs include, but are not limited to, the following:

  • Providing prevention information to individuals and groups known to be at risk for resonance disorders, as well as to individuals working with those at risk.
  • Educating other professionals on the needs of individuals with resonance disorders and the role of SLPs in diagnosing and managing resonance disorders.
  • Screening (including hearing screening) of individuals who present with signs and symptoms consistent with a resonance disorder and determining the need for further assessment and/or referral for other services.
  • Conducting a comprehensive, culturally and linguistically appropriate assessment of speech and resonance problems associated with resonance disorders, including perceptual, aerodynamic, and acoustic assessment of speech as well as evaluation of articulation when abnormal productions are noted.
  • Conducting and interpreting imaging studies of the velopharynx during speech to assist in diagnosis and treatment planning (e.g., nasopharyngoscopy, videofluoroscopy, magnetic resonance imaging), when indicated.
  • Differentially diagnosing resonance disorders.
  • Collaborating with physicians and/or the cleft craniofacial team to determine etiology.
  • Referring to other professionals to rule out other conditions and to facilitate access to comprehensive services.
  • Referring to a craniofacial or cleft palate team for further assessment of individuals with suspected velopharyngeal dysfunction (with or without cleft palate).
  • Contributing to decisions about the management of resonance disorders, including behavioral speech therapy, as well as surgical and prosthetic treatments.
  • Developing treatment plans, providing treatment, documenting progress, and determining appropriate dismissal criteria.
  • Counseling individuals with resonance disorders and their families regarding communication-related issues and providing education aimed at preventing further complications related to these conditions.
  • Consulting and collaborating with other professionals, family members, caregivers, and others to facilitate program development and to provide supervision, evaluation, and/or expert advice or opinion, as appropriate.
  • Serving as an integral member of an interdisciplinary team working with individuals with resonance disorders and their families/caregivers—see ASHA’s resources on interprofessional education/interprofessional practice (IPE/IPP) and person- and family-centered care.
  • Remaining informed of research in the area of resonance disorders and helping to advance the knowledge base related to the nature and treatment of these conditions.
  • Advocating for individuals with resonance disorders and their families at the local, state, and national levels.
  • Providing quality control and risk management.

As indicated in ASHA’s Code of Ethics (ASHA, 2023), SLPs who serve this population should be specifically educated and appropriately trained to do so.

See the Assessment section of the Velopharyngeal Dysfunction Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective, as they relate to resonance disorders.

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

Assessment includes evaluation of oral, nasal, and velopharyngeal (VP) function for speech production. The goal is to help determine if an individual would benefit from speech therapy and/or if medical (i.e., surgical or prosthetic) intervention might be warranted. The SLP conducts the assessment alone or as a member of a collaborative team that may include family members or care partners as well as other relevant professionals (e.g., otolaryngologist, surgeon, or prosthodontist).

Differential diagnosis is important during assessment and treatment selection to distinguish VP mislearning from other causes of velopharyngeal dysfunction (VPD). Referral to an appropriate team (e.g., craniofacial, cleft palate, or VPD team) is necessary if differential diagnosis cannot be determined during initial assessment or if it is determined that surgical or prosthodontic treatment is warranted.


Screening for suspected resonance disorders identifies the need for additional and/or more comprehensive assessment but does not provide a diagnosis. Clinicians must consider the norms of a particular language spoken as well as linguistic variance and/or influence when screening an individual’s speech for signs of resonance disorder.

Screening typically includes the following.

Speech Screening

  • Obtain a limited speech sample in all languages spoken to look for
    • signs and symptoms of a resonance disorder, including sounds affected, consistency of symptoms, and severity;
    • the presence of nasal emission (obligatory or compensatory/learned); and
    • the presence and type of articulation errors.
  • Perform an oral exam to look for anatomical/structural differences (e.g., cleft-related such as submucous cleft, fistula, or bifid uvula; non–cleft-related such as enlarged tonsils).

See the Assessment section of ASHA’s Practice Portal page on Cleft Lip and Palate for further details related to screening in persons with cleft lip and palate.

Hearing Screening

  • Conduct a hearing screening to identify individuals at risk for hearing loss who require referral to audiology for full hearing evaluation and management.
  • Set up a monitoring program to rescreen hearing as needed if the hearing screening is passed.

See ASHA’s Practice Portal pages on Adult Hearing Screening and Childhood Hearing Screening for information about hearing screenings.

Comprehensive Assessment

See ASHA’s Practice Portal resource, Comprehensive Assessment for Cleft Lip and Palate and Resonance. Some components of the comprehensive assessment for resonance disorders are similar to those of the comprehensive assessment for cleft lip and palate.

Consistent with the World Health Organization’s International Classification of Functioning, Disability and Health (ICF) framework (ASHA, 2023; World Health Organization, 2001), assessment is conducted to identify and describe

  • impairments in body structure and function, including underlying strengths and weaknesses related to resonance factors that affect communication performance;
  • comorbid deficits or conditions, such as developmental disabilities, syndromes, neuromuscular diseases, or hearing loss;
  • limitations in activity and participation, including functional communication in everyday communication contexts (see, e.g., Skirko et al., 2015);
  • 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 of the individual and family.

See ASHA’s resource on the International Classification of Functioning, Disability, and Health (ICF) for examples of ICF handouts specific to selected disorders.

Assessment may include instrumental evaluation if available and appropriate. Acoustic/spectral correlates of hypernasality are well known and include (a) reduced amplitude of the first formant (F1); (b) the appearance of a “nasal formant” typically below F1; (c) shifts in the frequency of formants, especially F1; and (d) increased bandwidths of formants. When hypernasality is severe, changes in acoustic/spectral properties of vowels can result in reduced intelligibility of a speaker.

Linguistic Considerations

Clinicians must consider the norms of a particular language spoken as well as linguistic variance and/or influence when evaluating an individual’s speech for signs of resonance disorder.

Individuals who speak a dialect or whose speech is influenced by native languages other than English may speak with a different tone or nasality than native English speakers or speakers of Mainstream American English dialect. These differences (e.g., glottalized tones or nasalized vowels) may affect perceptual judgments of nasality. Consequently, clinicians who are unfamiliar with the linguistic characteristics of the individual’s dialect or accent may have difficulty distinguishing a resonance difference from a resonance disorder (Bae et al., 2020; Velik et al., 2019).

Regardless of the language spoken, vowels (particularly high vowels) and pressure consonants are most vulnerable to VPD. Clinicians need to consider the presence and frequency of occurrence of these sounds in a particular language, as well as the degree of nasality produced by typical speakers of that language (Cordero, 2008; Lee et al., 2008; Willadsen & Henningsson, 2011). The presence of lexical tones (e.g., in tonal languages such as Cantonese) should also be taken into consideration when assessing possible VPD (Cordero, 2008), as tonal languages have been shown to present with different levels of nasalance compared to nontonal languages (see V. T. Nguyen et al., 2019, and D. M. Nguyen et al., 2021, for examples).

See ASHA’s Practice Portal page on Cultural Responsiveness and ASHA’s resource on phonemic inventories and cultural and linguistic information across languages for additional support.

Special Considerations: Deaf and Hard of Hearing

There is no “one size fits all” communication approach for those who are identified as deaf and hard of hearing. Language may be manual (e.g., American Sign Language), spoken (oral/aural), or both (total communication). Individuals identified as deaf and hard of hearing who chose spoken language for communication can exhibit resonance disorders characterized by hypernasality or hyponasality, mixed resonance, or cul-de-sac resonance. In most cases, these resonance problems result from poor control of the VP valve due to limited auditory feedback as a result of the hearing loss. Despite having normal structure and muscle movement, the VP valve may lack rhythm and timing. These individuals may have speech characteristics including abnormal resonance on vowels and nasal consonants (Coelho et al., 2015). It is important that other anatomical causes of resonance disorder be ruled out, particularly if hearing loss is secondary to a syndrome. Please see ASHA’s Practice Portal page on Language and Communication of Deaf and Hard of Hearing Children for further information on this population.

See the Treatment section of the Velopharyngeal Dysfunction Evidence Map for pertinent scientific evidence, expert opinion, and client/caregiver perspective, as they relate to resonance disorders.

Treatment is indicated for individuals of all ages when their ability to communicate effectively is impaired because of resonance and related articulation disorders. The goal of treatment is to achieve improved resonance to facilitate functional oral communication.

Consistent with the World Health Organization (2001) framework, treatment is designed to

  • capitalize on strengths and address weaknesses related to underlying structures and functions that affect resonance and articulation;
  • facilitate activities and participation by helping the individual acquire new skills and strategies; and
  • modify contextual factors to reduce barriers and enhance facilitators of successful communication and participation, including identification and use of appropriate accommodations.

Treatment procedures and approaches discussed below include

  • surgical management,
  • prosthetic management,
  • pharmacologic management, and
  • behavioral speech therapy.

Treatment selection considers the cause of the resonance disorder; the appropriateness of treatment for the individual’s chronological and developmental age; and the individual’s medical status, physical and sensory abilities, cognitive status, and cultural and linguistic background. Goals for individuals who speak a language other than English consider their linguistic background.

See ASHA’s Practice Portal resource, Treatment Decision Tree for Managing Speech Problems Associated with Cleft Palate and VPD for more information.

Surgical Management


Surgical management is the most common treatment for hypernasal speech due to velopharyngeal insufficiency (VPI; structural) and may also be used to treat oronasal fistulas that are symptomatic for speech. Procedures include the following (Tse et al., 2023):

Palate-based surgery, such as double-opposing Z-plasty, soft palate elongation, midline incision, and intravelar veloplasty. These surgeries are done to repair the primary muscle and reconstruct the palate to create favorable anatomy for velopharyngeal (VP) function.

Pharynx-based surgery, such as pharyngeal flap (flap raised from the posterior pharyngeal wall and surgically connected to the velum to close the pharyngeal port at midline while leaving the lateral ports open for nasal breathing and the production of nasal sounds) and sphincter pharyngoplasty (flaps raised from the posterior pharyngeal wall and surgically transposed to a horizontal inset along the posterior pharyngeal wall to reduce the diameter of the VP port).

Augmentation, such as fat grafting to fill in small VP gaps.

Combinations, to include the combination of any of the above surgical options such as double-opposing Z-plasty plus sphincter pharyngoplasty.


Surgical management for hyponasality involves procedures to correct anatomical sources of obstruction. Procedures include

  • tonsillectomy/adenoidectomy,
  • removal of nasal polyps,
  • surgery to correct a deviated septum,
  • surgical removal of the tissue or bone of the nasal passage to treat choanal atresia, and
  • surgical reconstruction to enlarge stenotic nares.

Prosthetic Management

Prosthetic management is uncommon in cases where resonance disorder is anatomically based but may be used for correcting resonance problems that are neurologically based, when surgical options are not recommended for the patient by the surgical team, or in rare cases where surgery has not completely resolved the problem. In cases when a consultation with a prosthodontist is being considered, SLPs may collaborate with that prosthodontist to assist in prosthetic design, positioning, or adjustments for optimal speech and swallowing function (Jackson, 2015).

Prosthetic management may include

  • a palatal obturator (to occlude an oronasal fistula),
  • a “speech bulb” (to occlude the velopharynx when there is VPI),
  • a palatal lift (to elevate the velum when there is VPI to compensate for poor velar mobility), and
  • a nasal obturator (used for individuals with VPI or velopharyngeal incompetency to decrease airflow during speech; can be used when a palatal lift is not an option).

Pharmacologic Management

Pharmacologic management is sometimes indicated when swelling or inflammation in the nasal cavity due to allergies or other irritants is causing or contributing to hyponasality. Medications include antihistamines or steroids delivered via nasal sprays or oral medication.

Behavioral Speech Therapy

Behavioral speech therapy cannot correct resonance disorders that are due to structural causes. Therapy is considered if it has been determined through an evaluation that the abnormal resonance is due to causes other than structural.

Behavioral speech therapy may be considered for the following:

  • Phoneme-specific nasal air emission or phoneme-specific hypernasality
    • Techniques and tools for targeting these errors include the following:
      • visual feedback provided by a dental mirror placed under the nose during production of oral target phonemes
      • visual biofeedback provided by the See-Scape™
      • auditory biofeedback provided by the Oral and Nasal Listener™
      • auditory biofeedback provided by a stethoscope (placed against the side of the nose)
      • plastic tubing or a drinking straw for self-monitoring one’s own productions (one end is placed at the patient’s/client’s nostril entrance, and the other end is placed by the ear)
      • a nasometer to monitor oral versus nasal speech and provide real-time visual feedback in cases of phoneme-specific disorders (see the Treatment section of ASHA’s Practice Portal page on Cleft Lip and Palate)
      • use of established/accurate phonemes to shape those affected by phoneme-specific nasal air emission (e.g., using /t/ to shape /s/)
  • Compensatory misarticulations that are present, regardless of the VP status (common in patients with a history of cleft palate)
    • Changing articulation placement on affected sounds can have some beneficial effect on perception of resonance (see initial therapy targets and strategies and techniques in the Treatment section of ASHA’s Practice Portal page on Cleft Lip and Palate).
  • Postoperative hypernasality
    • Persistent hypernasality after VP surgery may be treated by speech therapy with biofeedback (see options above); the potential for adequate VP closure during speech should be confirmed prior to initiating therapy. Various biofeedback techniques may be tried, including nasoendoscopy and/or nasometry. Displaying “oralance” rather than “nasalance” during nasometry biofeedback may be effective in increasing a speaker’s overall oral resonance, especially if loudness is reduced (Zajac & Vallino, 2016).
    • Hypernasality that persists more than a few months post-surgery should be referred to the cleft palate/craniofacial or velopharyngeal dysfunction team for reassessment and consideration of possible surgical revision and/or prosthetic management.
  • Muscle weakness/dysarthria resulting in hypernasality
    • Compensate for persistent resonance disorder—use techniques specific to dysarthria, including modifying the speech pattern (e.g., clear speech, loud speech).
    • VP resistance treatment—continuous positive airway pressure for resistance training during speech (Cahill et al., 2004; Kollara et al., 2014; Kuehn, 1997; Kuehn et al., 2002). The goal of this therapy is to increase velar muscle strength and endurance during speech.
    • Expiratory muscle strength training (EMST) involves the use of an external device to mechanically overload the expiratory muscles. EMST uses exercise to increase maximum expiratory pressure. SLPs typically use EMST to treat voice disorders, but EMST may also have potential for resonance disorder treatment.
  • Articulation errors secondary to apraxia of speech (work on planning/coordination of VP movement)
    • As articulation improves, perception of resonance may also improve as the velum articulates more accurately.
  • Idiopathic hypernasality
    • Speech therapy may be tried on a trial basis in cases of idiopathic hypernasality when there is no confirmed structural anomaly.

Special Populations: Deaf and Hard of Hearing

SLPs and audiologists provide therapy to support the language and manner that match individuals’ communication preferences (e.g., signed language vs. spoken language). Individuals who are deaf and hard of hearing often have difficulty monitoring VP function due to lack of, or decreased, auditory feedback. Hearing aids and cochlear implants serve to assist the individual’s auditory feedback mechanisms, thereby improving self-monitoring skills.

Cochlear implants have been shown to increase understanding of speech and help improve the resonance of oral speakers (Sebastian et al., 2015). Improved nasalance scores following cochlear implantation demonstrate the role of auditory feedback in helping monitor VP function (Hassan et al., 2012; L. H. P. Nguyen et al., 2008).

After obtaining hearing aids or receiving cochlear implantation, individuals often benefit from aural (re)habilitation to improve listening and communication skills. Additional goals may address speech (e.g., improving consonant production) and resonance, taking advantage of improved auditory feedback. For information on aural (re)habilitation in children with cochlear implants, see ASHA’s Practice Portal page on Cochlear Implants.

Individuals who are profoundly deaf may benefit from visual and tactile feedback to normalize hypernasal speech (L. H. P. Nguyen et al., 2008).

These feedback techniques may include

  • visual monitoring of nasal airflow with a mirror or nasometer and
  • tactile feedback during chewing exercises associated with vibratory sensations in the nasal and facial bones or during humming.

Please see ASHA’s Practice Portal page on Language and Communication of Deaf and Hard of Hearing Children for further information on this population.

Collaboration in Treatment

Community-based SLPs—including private practitioners and school-based SLPs—who are involved in the treatment of individuals with resonance disorders are encouraged to collaborate with cleft palate/craniofacial teams and other appropriate professionals, including otolaryngologists and plastic/craniofacial surgeons, to maximize speech outcomes. School-based and private practice/clinic-based SLPs are encouraged to refer to these teams as needed to ensure quality of care. See also ASHA’s resources on collaboration and teaming and interprofessional education/interprofessional practice (IPE/IPP).

Service Delivery

In addition to determining the type of speech and language treatment that is optimal for individuals with resonance disorders, SLPs consider other service delivery variables—including format, provider, dosage, timing, and setting—that may affect treatment outcomes.

  • Format—whether a person is seen for treatment one-on-one (i.e., individual) or as part of a group; telepractice can be used to deliver face-to-face services remotely. See ASHA’s Practice Portal page on Telepractice.
  • Provider—the person providing treatment (e.g., SLP, trained volunteer, care partner).
  • Dosage—the frequency, intensity, and duration of service.
  • Timing—when the intervention is conducted relative to the diagnosis.
  • Setting—the location of treatment (e.g., home, community-based, school).

For further information, please see the Service Delivery section in ASHA’s Velopharyngeal Dysfunction Evidence Map.

ASHA Resources

Other Resources

This list of resources is not exhaustive, and the inclusion of any specific resource does not imply endorsement from ASHA.

American Speech-Language-Hearing Association. (2016). Scope of practice in speech-language pathology [Scope of practice].

American Speech-Language-Hearing Association. (2023). Code of ethics [Ethics].

Bae, Y., Lee, S. A. S., Velik, K., Liu, Y., Beck, C., & Fox, R. A. (2020). Differences in nasalance and nasality perception between Texas South and Midland dialects. The Journal of the Acoustical Society of America, 147(1), 568–578.

Barata, L. F., de Carvalho, G. B., Carrara-de Angelis, E., de Faria, J. C. M., & Kowalski, L. P. (2013). Swallowing, speech and quality of life in patients undergoing resection of soft palate. European Archives of Oto-Rhino-Laryngology, 270(1), 305–312.

Basta, M. N., Silvestre, J., Stransky, C., Solot, C., Cohen, M., McDonald-McGinn, D., Zackai, E., Kirschner, R., Low, D. W., Randall, P., LaRossa, D., & Jackson, O. A. (2014). A 35-year experience with syndromic cleft palate repair: Operative outcomes and long-term speech function. Annals of Plastic Surgery, 73(Suppl. 2), S130–S135.

Baudonck, N., Van Lierde, K., D’haeseleer, E., & Dhooge, I. (2015). Nasalance and nasality in children with cochlear implants and children with hearing aids. International Journal of Pediatric Otorhinolaryngology, 79(4), 541–545.

Cahill, L. M., Turner, A. B., Stabler, P. A., Addis, P. E., Theodoros, D. G., & Murdoch, B. E. (2004). An evaluation of continuous positive airway pressure (CPAP) therapy in the treatment of hypernasality following traumatic brain injury: A report of 3 cases. The Journal of Head Trauma Rehabilitation, 19(3), 241–253.

Coelho, A. C., Medved, D. M., & Brasolotto, A. G. (2015). Hearing loss and the voice. In F. Bahmad Jr. (Ed.), Update on hearing loss. IntechOpen.

Cordero, K. N. (2008). Assessment of cleft palate articulation and resonance in familiar and unfamiliar languages: English, Spanish, and Hmong [Unpublished doctoral dissertation]. University of Minnesota. [PDF]

Crockett, D. J., Ahmed, S. R., Sowder, D. R., Wootten, C. T., Chinnadurai, S., & Goudy, S. L. (2014). Velopharyngeal dysfunction in children with Prader-Willi syndrome after adenotonsillectomy. International Journal of Pediatric Otorhinolaryngology, 78(10), 1731–1734.

Filip, C., Feragen, K. B., Lemvik, J. S., Lindberg, N., Andersson, E.-M., Rashidi, M., Matzen, M., & Høgevold, H. E. (2015). Multidisciplinary aspects of 104 patients with Pierre Robin sequence. The Cleft Palate–Craniofacial Journal, 52(6), 732–742.

Golinko, M. S., LeBlanc, E. M., Hallett, A. M., Alperovich, M., & Flores, R. L. (2016). Long-term surgical and speech outcomes following palatoplasty in patients with Treacher-Collins syndrome. The Journal of Craniofacial Surgery, 27(6), 1408–1411.

Goudy, S., Ingraham, C., & Canady, J. (2011). The occurrence of velopharyngeal insufficiency in Pierre Robin Sequence patients. International Journal of Pediatric Otorhinolaryngology, 75(10), 1252–1254.

Ha, S., Koh, K. S., Moon, H., Jung, S., & Oh, T. S. (2015). Clinical outcomes of palatal surgery in children with nonsyndromic cleft palate with and without lip. BioMed Research International, 2015, Article 185459.

Hassan, S. M., Malki, K. H., Mesallam, T. A., Farahat, M., Bukhari, M., & Murry, T. (2012). The effect of cochlear implantation on nasalance of speech in postlingually hearing-impaired adults. Journal of Voice, 26(5), 669.e17–669.e22.

Isotalo, E., Pulkkinen, J., & Haapanen, M.-L. (2007). Speech in 6 year old children with sub-mucous cleft palate. The Journal of Craniofacial Surgery, 18(4), 717–724.

Jackson, M. (2015). Prosthodontics rehabilitation in velopharyngeal insufficiency. In N. Raol & C. J. Hartnick (Eds.), Surgery for pediatric velopharyngeal insufficiency (Vol. 76, pp. 41–49). Karger.

Jackson, O., Crowley, T. B., Sharkus, R., Smith, R., Jeong, S., Solot, C., & McDonald-McGinn, D. (2019). Palatal evaluation and treatment in 22q11.2 deletion syndrome. American Journal of Medical Genetics: Part A, 179(7), 1184–1195.

Jackson, O., Stransky, C. A., Jawad, A. F., Basta, M., Solot, C., Cohen, M., Kirschner, R., Low, D. W., Randall, P., & LaRossa, D. (2013). The Children’s Hospital of Philadelphia modification of the Furlow double-opposing Z-palatoplasty: 30-year experience and long-term speech outcomes. Plastic and Reconstructive Surgery, 132(3), 613–622.

Khami, M., Tan, S., Glicksman, J. T., & Husein, M. (2015). Incidence and risk factors of velopharyngeal insufficiency postadenotonsillectomy. Otolaryngology–Head and Neck Surgery, 153(6), 1051–1055.

Kirschner, R. E. (2005). Palatal anomalies and velopharyngeal dysfunction associated with velo-cardio-facial syndrome. In K. C. Murphy & P. J. Scambler (Eds.), Velo-cardio-facial syndrome: A model for understanding microdeletion disorders (pp. 83–104). Cambridge University Press.

Kocaaslan, F. N. D., Sendur, S., Koçak, I., & Çelebiler, Ö. (2020). The comparison of Pierre Robin sequence and non-syndromic cleft palate. The Journal of Craniofacial Surgery, 31(1), 226–229.

Kollara, L., Schenck, G., & Perry, J. (2014). Continuous positive airway pressure (CPAP) therapy for the treatment of hypernasality: A single case study. Perspectives on Speech Science and Orofacial Disorders, 24(2), 48–58.

Kuehn, D. P. (1997). The development of a new technique for treating hypernasality: CPAP. American Journal of Speech-Language Pathology, 6(4), 5–8.

Kuehn, D. P., Imrey, P. B., Tomes, L., Jones, D. L., O’Gara, M. M., Seaver, E. J., Smith, B. E., Van Demark, D. R., & Wachtel, J. M. (2002). Efficacy of continuous positive airway pressure for treatment of hypernasality. The Cleft Palate–Craniofacial Journal, 39(3), 267–276.

Kummer, A. W. (2014). Resonance and velopharyngeal dysfunction (VPD). In A. W. Kummer (Ed.), Cleft palate and craniofacial anomalies: Effects on speech and resonance (pp. 182–224). Cengage Learning.

Kummer, A. W., Marshall, J. L., & Wilson, M. M. (2015). Non-cleft causes of velopharyngeal dysfunction: Implications for treatment. International Journal of Pediatric Otorhinolaryngology, 79(3), 286–295.

Lee, A., Brown, S., & Gibbon, F. E. (2008). Effect of listeners’ linguistic background on perceptual judgements of hypernasality. International Journal of Language & Communication Disorders, 43(5), 487–498.

Nasser, M., Fedorowicz, Z., Newton, T., & Nouri, M. (2008). Interventions for the management of submucous cleft palate. Cochrane Database of Systematic Reviews, 23, 1–16.

Nguyen, D. M., Lee, S. A. S., Hayakawa, T., Yamamoto, M., & Natsume, N. (2021). Normative nasalance values in Vietnamese with southern dialect: Vowel and tone effects. Journal of Speech, Language, and Hearing Research, 64(5), 1515–1525.

Nguyen, L. H. P., Allegro, J., Low, A., Papsin, B., & Campisi, P. (2008). Effect of cochlear implantation on nasality in children. Ear, Nose & Throat Journal, 87(3), 138–140.

Nguyen, V. T., Lehes, L., Truong, T. T. H., Hoang, T. V. A., & Jagomägi, T. (2019). Normative nasalance scores for Vietnamese-speaking children. Logopedics Phoniatrics Vocology, 44(2), 51–57.

Novotný, M., Rusz, J., Čmejla, R., Růžičková, H., Klempíř, J., & Růžička, E. (2016). Hypernasality associated with basal ganglia dysfunction: Evidence from Parkinson’s disease and Huntington’s disease. PeerJ, 4, e2530.

Peterson-Falzone, S. J., Hardin-Jones, M. A., & Karnell, M. P. (2010). Cleft palate speech. Mosby.

Reiter, R., Brosch, S., Wefel, H., Schlömer, G., & Haase, S. (2011). The submucous cleft palate: Diagnosis and therapy. International Journal of Pediatric Otorhinolaryngology, 75(1), 85–88.

Sebastian, S., Sreedevi, N., Lepcha, A., & Mathew, J. (2015). Nasalance in cochlear implantees. Clinical and Experimental Otorhinolaryngology, 8(3), 202–205.

Shprintzen, R. J. (1997). Genetics, syndromes, and communication disorders. Singular.

Shprintzen, R. J. (2000). Syndrome identification for speech-language pathology: An illustrated pocket guide. Singular.

Skirko, J. R., Weaver, E. M., Perkins, J. A., Kinter, S., Eblen, L., Martina, J., & Sie, K. C. Y. (2015). Change in quality of life with velopharyngeal insufficiency surgery. Otolaryngology–Head and Neck Surgery, 153(5), 857–864.

Spruijt, N. E., ReijmanHinze, J., Hens, G., Vander Poorten, V., & Mink van der Molen, A. B. (2012). In search of the optimal surgical treatment for velopharyngeal dysfunction in 22q11.2 deletion syndrome: A systematic review. PLOS ONE, 7(3), Article e34332.

Tang, J. A., Salapatas, A. M., Bonzelaar, L. B., & Friedman, M. (2017). Long-term incidence of velopharyngeal insufficiency and other sequelae following uvulopalatopharyngoplasty. Otolaryngology–Head and Neck Surgery, 156(4), 606–610.

Tse, R. W., Sie, K. C., Tollefson, T. T., Jackson, O. A., Kirshner, R., Fisher, D. M., Bly, R., Arneja, J. S., Dahl, J. P., Soldanska, M., & Sitzman, T. J. (2023). Surgery for velopharyngeal insufficiency following cleft palate repair: An audit of contemporary practice and proposed schema of techniques and variations. The Cleft Palate–Craniofacial Journal. Advance online publication.

Vallino, L. D., Zuker, R., & Napoli, J. A. (2008). A study of speech, language, hearing, and dentition in children with cleft lip only. The Cleft Palate–Craniofacial Journal, 45(5), 485–494.

van Borsel, J. (2004). Voice and resonance disorders in genetic syndromes: A meta-analysis. Folia Phoniatrica et Logopaedica, 56(2), 83–92.

Velik, K., Bae, Y., & Fox, R. A. (2019). Effects of regional dialect on oral–nasal balance and nasality perception. Clinical Linguistics & Phonetics, 33(7), 587–600.

Willadsen, E., & Henningsson, G. (2011). Cross-linguistic perspectives on speech assessment in cleft palate. In S. Howard & A. Lohmander (Eds.), Cleft palate speech: Assessment and intervention (pp. 167–180). Wiley.

World Health Organization. (2001). International classification of functioning, disability and health.

Yorkston, K. M., Beukelman, D. R., Strand, E. A., & Hakel, M. (2010). Management of motor speech disorders in children and adults. Pro-Ed.

Ysunza, P. A., Jackson, I., & Lozon, C. L. (2013). Diagnosis and management of velopharyngeal insufficiency associated with chromosomal syndromes. Cloning & Transgenesis, 2, 1–5.

Zajac, D. J., & Vallino, L. D. (2016). Evaluation and management of cleft lip and palate: A developmental perspective. Plural.


Content for ASHA’s Practice Portal is developed through a comprehensive process that includes multiple rounds of subject matter expert input and review. ASHA extends its gratitude to the following subject matter experts who were involved in the development of the Resonance Disorders page:

  • Adriane L. Baylis, PhD, CCC-SLP
  • Kelly Nett Cordero, PhD, CCC-SLP
  • Scott Dailey, PhD, CCC-SLP
  • Kristen DeLuca, MS, CCC-SLP
  • Angela J. Dixon, MA, CCC-SLP
  • Mark Hakel, PhD, CCC-SLP
  • Sara L. Kinter, MA, CCC-SLP
  • Ann W. Kummer, PhD, CCC-SLP
  • Katherine Monaghan McConville, MA, CCC-SLP
  • Jaime L. Perry, PhD, CCC-SLP
  • Robert J. Shprintzen, PhD, CCC-SLP
  • Margaret M. Wilson, MA, CCC-SLP
  • David J. Zajac, PhD, CCC-SLP

Citing Practice Portal Pages

The recommended citation for this Practice Portal page is:

American Speech-Language-Hearing Association. (n.d.). Resonance disorders [Practice portal].

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.

ASHA Corporate Partners