Detection of Glottal Activity Errors in Production of Stop Consonants in Children with Cleft Lip and Palate

Individuals with cleft lip and palate (CLP) alter the glottal activity characteristics during the production of stop consonants. The presence/absence of glottal vibrations during the production of unvoiced/voiced stops is referred as glottal activity error (GAE). In this work, acoustic-phonetic and production based knowledge of stop consonants are exploited to propose an algorithm for the automatic detection of GAE. The algorithm uses zero frequency filtered and band-pass (500-4000 Hz) filtered speech signals to identify the syllable nuclei positions, followed by the detection of glottal activity characteristics of consonant present within the syllable. Based on the identified glottal activity characteristics of consonant and a priori voicing information of target stop consonant, the presence or absence of GAE is detected. The algorithm is evaluated over the database containing the responses of normal children and children with repaired CLP for the target consonant-vowel-consonant-vowel words with stop consonants.