Patterns of oral-nasal balance in normal speakers with and without cleft palate

The aero-acoustic aspects of nasalization that distinguish speakers with velopharyngeal adequacy from those with velopharyngeal inadequacy are well known. Differences in aerodynamic aspects of nasalization also have been demonstrated in normal speakers with cleft palate and their noncleft counterparts. The purpose of this study was to compare the amplitude and temporal patterns of oral-nasal balance in speakers with cleft palate and normal speech to those with normal speech without cleft palate.

Using the Nasal Accelerometric Vibrational Index technique, the time course and amplitude of oral-nasal balance were studied in 10 children with cleft palate and velopharyngeal adequacy and 10 noncleft controls. The speech sample included syllable, word, and sentence contexts, most of which were devoid of nasal consonants.

The results indicate few differences between the two groups in contexts devoid of nasal consonants. However, significant differences were evident with regard to temporal aspects of oral-nasal balance in a nasal-oral consonant word context.

Subtle structural-motor differences that may exist between normal speakers with and without cleft palate may be more evident when the spatiotemporal requirements for velar movement become more complex and result in a greater possible combination of oral-nasal impedance ratios.