Towards a study of the rhythmic structural in dysarthric speech

Author(s)

Jussara Melo Vieira

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Estudos da Linguagem
• Defense date: 2007-02-23

Examining board members

Plinio Almeida Barbosa; Maria Irma Hadler Coudry; Mair Ines Pegoraro Krook; Sandra Madureira; Zuleica Antonia de Camargo

• Advisor: Plinio Almeida Barbosa

Abstract

Dysarthria is a speech disorder caused by neuromotors problems. These neuromotors problems may cause breath, phonation, resonance and speech articulation disturbance. The cause of these neuromotors problems can be the traumatic brain injury (TBI). TBI is a lesion that result of cerebral aggression, a collision in the head/or a fall happening cranial breaking. Dysarthric speech can have too velopharyngeal dysfunction by total/partial paralysis soft palate. In case of soft palate palsy the hypernasality may be present, with emission of nasal air during oral sounds. In order to deal with hypernasality and nasal air emission a palatal lift (PL) is indicated. The use of PL stimulates the correct movement of the soft palate, which produces the appropriate closure of the velopharyngeal port. Rhythm speech can be altered in dysarthric speech. We realize then a study of the rhythmic structure of the dysarthric speech by TBI. For doing so, eight dysarthric speaker?s readings during prosthesis treatment with the palatal lift, are compared with readings without prosthesis, with a reference speaker and a French dysarthric speaker. These comparisons are done by analyzing vowel-to-vowel units (VV), stress groups, phrase stress and silent pauses under the theoretical framework of Barbosa (2006)?s speech rhythm model applied to Brazilian Portuguese. In the eight readings of the Brazilian dysarthric speaker, there were reductions on the number of silent pauses and pause occurrence. An increase of speech rate was also observed. The results showed that there is no distinction in rhythmic structure with and without prosthesis. The comparative analysis between the Brazilian dysarthric speaker and the reference speaker showed significant differences in speech rate and silent pause duration, but no significant difference in the duration of stress groups or in the number of VV units. The comparative analysis between the Brazilian dysarthric speaker and the French dysarthric speaker showed no significant differences in speech rate, articulation rate and number of VV units inside stress groups. As regards the syntax-prosody interface, the syntactic markers IDF (strong independency) and COORD (coordinated conjunction independency) were significant for both the Brazilian dysarthric and the reference speaker. However, these markers were not significant for the French dysarthric speaker. This work reinforces the importance of considering both linguistics and biomechanics aspects on the analysis of dysarthric speech (AU)