Resonance measures the vibration produced when speaking, in both your pharynx (throat) and oral cavity (mouth). An imbalance can create abnormal speech sounds known as resonance disorders that disrupt communication with others.
Hyponasality and hypernasality are among the most frequently occurring issues, occurring when certain consonant sounds don’t close properly when pronouncing them through consonant sounds such as those found in words such as ‘d’ and ‘th’.
What is Resonance?
Resonance refers to the vibration of sound waves against structures within the body. To produce clear speech, individuals need sufficient resonance in their bodies in order to produce adequate resonance levels in their voice; nasal, pharyngeal and head resonance can occur; those suffering from resonance disorders may experience distortions which compromise its quality.
Normal voice production involves striking a balance of sound energy between oral and nasal cavities depending on the sounds being produced, with resonance being distributed more heavily to oral cavities for English spoken sounds than for those from other languages. There can be various variations to how this balance is reached depending on language used when speaking it and vocal fold and muscle function – with English-spoken languages needing greater resonance from oral cavities than others.
Oral resonance occurs as a result of hard and soft areas on the roof of the mouth (the palate), making sounds that resonate both orally and nasally. To produce natural sounding sounds it is crucial that there be an ideal balance of oral resonance compared to nasal resonance; too much oral resonance creates hyponasality while too little oral resonance produces hypernasality.
Pharyngeal resonance occurs when sounds produced cause vibrations in the pharynx (located at the throat). You could compare its impact to that of changing bass/treble sliders on your stereo to match whatever music was playing – or conversely how much resonance is applied depending on what sound type or volume of speech production occurs and your personal taste.
Some individuals experience issues with their head resonance, meaning the structures above the neck do not vibrate as intended when speaking. This phenomenon is most frequently found among singers as they sing higher notes but can also affect some women. Distortions caused by this issue are usually described as nasality and denasality as they can often be difficult to identify individually.
Hyponasal Resonance
Resonance is a quality of the voice created through sound vibrations, air flow and air pressure. A normal balance exists between oral and nasal sound energy production; if this balance becomes off, an individual may suffer from resonance disorder and require treatment from a speech pathologist in order to improve their voice.
Speech pathologists specialize in evaluating resonance disorders such as hypernasality and hyponasality, with hypernasality being an issue where voice sounds have an nasal quality due to overproduction or blockage in the nose; hypernasality could also be related to medical issues like deviated septum or allergies.
Hyponasality occurs when there is an inadequate production of nasal sound energy. This could be caused by blockages in your nose or it could also be related to medical issues like cleft lip/palate syndrome or neurological conditions that require medications for treatment.
Studies have demonstrated that individuals with hearing impairment often exhibit problems of resonance. Resonance issues vary considerably in severity among HI individuals and its difficulty has hindered diagnosis and treatment efforts for these difficulties. One method developed to assess these difficulties is perceptual rating of focus resonance focus rating.
Recent research has demonstrated the efficacy of this approach to assessing type of resonance among hearing impaired populations. Raters were able to accurately classify various forms of nasality found among these individuals. Distortions may either feature nasal focus of resonance, pharyngeal focus of resonance or mixed hypernasality/hyponasality characteristics.
One straightforward method to quickly assess whether someone has hypernasality or hyponasality is by having them look in a hand mirror while pronouncing “m”, “n”, and “ng”. Their uvula should move up and down with these sounds; otherwise they are likely experiencing either hypernasality or mild cases of hyponasality.
Hypernasal Resonance
Resonance occurs when sound vibrations bounce off of objects. When speaking, sounds can resonate in different areas of the mouth and nasal cavity. Hypernasal resonance occurs when your speech emerges through your nose instead of through your mouth; this could be learned behavior or due to congenital conditions.
Speech therapy for hypernasal resonance is the best way to address it. There are various speech therapists who specialize in treating this disorder, so if you or your child experience hypernasal resonance it’s wise to contact a specialist before it worsens further.
Normal resonance can be achieved through an appropriate balance of oral and nasal sound energy based on the intended speech sound, including vowels, voiced oral consonants and nasal consonants in different languages and dialects. “Hypernasality” simply refers to when there is too much nasal enhancement of certain sounds – typically vowels or vowel-like consonants like /m,n,ng/ should not experience nasal enhancement. Hypernasality may occur mildly, moderately or severely and it may either all the time or only occasionally.
Clinics use numerous speech tests to evaluate resonance. One of the most reliable techniques is passage tasks containing varied proportions of nasal and oral stops and fricatives; another method utilizes a device known as nasometer to measure nasal and oral sound pressures; this yields an index known as nasalance that can be compared with values obtained from normal hearing people to accurately judge hypernasality.
A nasometer may be difficult for children with narrow nasal cavities to use effectively, and can also be quite expensive and require training to operate effectively. An alternative technique called “cul-de-sac testing or nasal occlusion” may be more convenient and easier for them.
Assist the speaker by having him or her repeat syllables with pressure-sensitive oral and nasal consonants while pinching and then releasing his nose. This allows one to identify whether sounds are being produced through either mouth, nasal cavity or both sources.
Velopharyngeal Incompetence
Velopharyngeal incompetence (VPI) occurs when the sphincter that closes during speech and swallowing fails to function as intended, leading to nasally speaking voices, difficulty chewing and swallowing, regurgitation of food into the nose or regurgitated liquid back up through the nasal cavity. VPI may occur with birth defects of the palate such as cleft palate or abnormally short soft palate, genetic conditions like Down syndrome and neurofibromatosis and even after having an adenoidectomy done.
Before considering surgery to repair VPI, cleft palate teams should first identify and assess for it. Craniofacial surgeons are specially trained to identify when the velum isn’t closing well enough and can offer specific recommendations about how best to solve this issue.
VPI is most often caused by an issue with the velum; specifically when it rests too low and does not touch the back wall of the throat when speech production occurs. Other structural and neurological issues that impact palate or sphincter function such as narrow or long palates, large tongues, abnormally deep pharynxes or cervical spine anomalies could also play a part.
Speech-language pathologists can assist clients living with VPD by teaching them how to utilize their lips and tongue more efficiently to produce more of the sounds desired through articulation therapy sessions. Furthermore, they may teach how to better use breath support and effort so that less air escapes through their nose during speech, replacing their habit of sending airflow through it with correct productions.
In cases of neurological issues such as childhood apraxia of speech, it is strongly advised that children be evaluated by both an experienced speech-language pathologist and neurosurgeon/neurologist to rule out potential complications, including cerebral palsy or traumatic brain injury which may affect velopharyngeal closure leading to hypernasality.
