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 /ɡ/).
- High vowels (/u, i/) are most susceptible to effects of hypernasality and are often the first vowels in which the listener notices its presence.
- Voiced pressure consonants may be perceived as their nasal cognates (e.g., /n/ for /d/ or /m/ for /b/).
- 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 /ɡ/ for /ŋ/)
- 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 due to an obstruction.
- 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.
- Co-occurrence of hypernasality, hyponasality, and/or cul-de-sac resonance in the same speech signal.
- Hypernasality and hyponasality can occur at different times during connected speech (e.g., with apraxia).
- Hypernasality and hyponasality may co-occur when VPD and any form of nasopharyngeal obstruction are present.