Analysis of cleft palate speech is commonly based on dividing speech into categories of passive speech characteristics (hypernasality, audible nasal air leakage, reduced pressure on consonants requiring high intra-oral pressure) and active speech characteristics (the use of alternative places of articulation and/or manner of articulation in consonant production) (Harding & Grunwell, 1998; Hutters & Brondsted, 1987). However, frameworks, speech outcomes and scales differ between different tools for assessment of cleft palate speech.
The choice of outcome measures is to some extent guided by the purpose of the assessment. For treatment planning and evaluation in the clinic, there may be a need for more detailed assessment and speech outcomes. However, the more detailed the assessment and the speech outcomes are, the more difficult it is to achieve consensus within and between judges. In research and quality development, it is important to use measures that have both high reliability and validity (that they measure what they are intended to measure).
The percentage consonants correct (PCC) is a measure of consonant proficiency, originally developed by Shriberg and Kwiatkowski (1982) as a measure of the proportion of correctly-articulated consonants in phonetic transcriptions of conversational speech, to assess severity of involvement. Single-word material can be used to assess PCC if the results are not to be related to severity of involvement (Shriberg et al., 1997). This has been done in cross-linguistic comparisons in the Scandcleft project (Willadsen et al., 2017). It is easier to achieve high agreement within and between judges in PCC (Klintö et al., 2022) than in phonetic transcriptions, however, the risk of chance agreement when calculating PCC needs to be considered (Sell & Sweeney, 2020).
Rating of perceived velopharyngeal competence (VPC), with the scale VPC-R was used within the Scandcleft project for cross-linguistic comparisons (Lohmander et al., 2009, Lohmander et al., 2017b). It has proved to be reliable and has been validated (Lohmander et al., 2017a). Perceived velopharyngeal competence is an overall assessment of the symptoms of velopharyngeal dysfunction (i.e., hypernasality, audible nasal air leakage, and reduced pressure on consonants requiring high intra-oral pressure) rated on a 3-point ordinal scale (competent/sufficient, marginally incompetent/insufficient, incompetent/insufficient). The assessment is based on the available speech material (single-words, sentence repetition and/or continuous speech).
* Harding A, Grunwell P. Active versus passive cleft-type speech characteristics. International Journal of Language & Communication Disorders, 1998;33:329–352.
* Hutters B, Brøndsted K. Strategies in cleft palate speech--with special reference to Danish. Cleft Palate Journal, 1987;24:126–136.
* Klintö K, Hagberg E, Havstam C, Nelli C, Okhiria Å, Brunnegård K. Reliability of data on percent consonants correct in the Swedish Cleft Lip and Palate Registry. Logopedics Phoniatrics Vocology 2022. Epub ahead of print.
* Lohmander A, Willadsen E, Persson C, Henningsson G, Bowden M, Hutters B. Methodology for speech assessment in the Scandcleft project--an international randomized clinical trial on palatal surgery: Experiences from a pilot study. Cleft Palate Craniofacial Journal, 2009;46:347–362.
* Lohmander A, Hagberg E, Persson C, Willadsen E, Lundeborg I, Davies J, et al. Validity of auditory perceptual assessment of velopharyngeal function and dysfunction - the VPC-Sum and the VPC-Rate. Clinical Linguistics & Phonetics, 2017a;31:589–597.
* Lohmander A, Persson C, Willadsen E, Lundeborg I, Alaluusua S, Aukner R, et.al. Scandcleft randomised trials of primary surgery for unilateral cleft lip and palate: 4. Speech outcomes in 5-year-olds - velopharyngeal competency and hypernasality. Journal of Plastic Surgery and Hand Surgery, 2017b;51:26-36
* Shriberg LD, Austin D, Lewis BA, McSweeny JL, Wilson DL. The percentage of consonants correct (PCC) metric: Extensions and reliability data. Journal of Speech, Language, and Hearing Research, 1997;40:708–722.
* Shriberg LD, Kwiatkowski J. Phonological disorders III: A procedure for assessing severity of involvement. The Journal of Speech and Hearing Disorders, 1982;47:256–270.
* Willadsen E, Lohmander A, Persson C, Lundeborg I, Alaluusua S, Aukner R, et al. Scandcleft randomised trials of primary surgery for unilateral cleft lip and palate: 5. Speech outcomes in 5-year-olds—consonant proficiency and errors. Journal of Plastic Surgery and Hand Surgery, 2017;51:38–51.
* Sell D, Sweeney T. Percent Consonant Correct as an outcome measure for cleft speech in an intervention study. Folia Phoniatrica et Logopaedica. 2020;72:143-151.