Barbara Gili FivelaUniversity of Salento, Italy
Title: The impact of dysarthria on phonological and sociophonetic information in dysarthric speech: on vowel production
The investigation regards Italian dysarthric speakers affected by Parkinson’s Disease, and the communication aims at reporting results on the acoustic analysis of the accuracy in their speech production at a given stage of the development of dysarthria. A decrease in speech accuracy is expected to have a stronger impact on speech intelligibility when it regards phonological units, i.e. units playing a role in differentiating meanings than when it affects sociophonetic markers, i.e. variants. The main goal of the work is to check if mild dysarthria still affects similarly the accuracy of production of phonological features and that of sociophonetic markers. The hypothesis is that phonological units are preserved by means of compensation strategies more than sociophonetic markers, due to the role of the former in warranting speech intelligibility (for phonological distinctions in Korean; for allophonic variants in English; for Italian). Eighteen Italian speakers from the Apulia region participated in the study: ten subjects suffering from Parkinson's Desease and mild hypokinetic-dysarthria (PDs, 5 from Bari and 5 from Lecce) and eight healthy-control speakers (HCs, 4 from Lecce and 4 from Bari). Subjects were chosen from Lecce and Bari as they differ in realizing sentence-final unstressed vowels . Participants were not cognitively impaired (MOCA >= 24) and were age matched as much as possible (average age: 63 y.o.). Subjects were recorded in ON-phase while performing (three times) a diadochokinetic task, involving three peripheral vowels (/i/, /a/, /u/), and while reading sentences ending with /a/ and being characterized by different pragmatic functions (declaratives and information seeking yes-no questions). Results confirm the hypothesis, asthe vowel space of PD and HC speakers differ, but PD vowels are still clearly discrete; however, only some PD productions by Bari speakers show changes in vowel quality in unstressed, final vowels.
Barbara Gili Fivela is associate professor at University of Salento (Lecce-Italy), where she is also vice-director of the research center CRIL (Centro di Ricerca Interdisciplinare sul Linguaggio). Since 2019, she has been the president of the Italian Association for Speech Sciences (AISV-Associazione Italiana Scienze della Voce, a Special Interest Group of ISCA, International Association of Speech Communication). Her main research interests regard the acoustics and kinematics of healthy and dysarthric speech, the phonology and phonetics of intonation, and second language learning phonological processes.