A diachronic study on Italian speech rhythm in Parkinson’s Disease

Abstract

Parkinson's Disease dysarthria affects the speech motor control, causing alterations at the suprasegmental level of speech. In previous researches, vowel percentage (%V) and the mean interval between two consecutive vowel onset points (VtoV) were effectively used in the synchronic description of the rhythmic variations of Italian PD speech, compared to healthy speech, even at a very early stage of the disease.This study aims at verifying the early alteration of PD speech rhythm using a diachronic approach. To reach this goal, a corpus of read speech produced by a single PD subject (female, 66 years old) has been collected, consisting of 15 radiophonic speech samples (about 100 s each) on the same topic, recorded between 2001 and 2021.The speech samples were manually segmented in consonantal and vocalic intervals by means of Praat, allowing the calculation of %V and VtoV.The results show an alteration of %V values since 2018, two years before the diagnosis and the insurgence of motor symptoms.Moreover, first results of the application of the automatic segmentation performed by SPPAS on a selection of PD speech samples will also be presented.

Analyzing changes in parkinsonian speech over time: a diachronic experimental phonetics study

“…The spectro-acoustic analysis of Alan Alda’s speech shows how approximately 5 years before the onset of motor symptoms (as reported by the actor himself) and the consequent diagnosis, the %V parameter undergoes a sudden increase, and then remains more or less constant in the following years, even during the period of pharmaceutical treatment. 8 These results confirm the findings of the two previous studies ( Pettorino et al, 2018 , 2022 ), in which the same methodology was applied on data from two PD speakers diagnosed when aged 30 and 65. 9 Even in those cases, a sharp increase in %V some years before diagnosis was detected, as long as a subsequent leveling.…”

“…It is worth noting that, as reported in Section 4, in a previous study ( Maffia et al, 2021 ) the speech of PD patients and healthy speakers was analyzed using the same metric applied here on Alan Alda’s speech (%V/VtoV). The results of this study, together with those of other works cited in the text ( Liss et al, 2009 ; Pettorino et al, 2016 , 2017 , 2018 , 2022 ), clarified that the proportion of vowel intervals (%V) is effective in discriminating PD speakers even in the very early stages of the disease. The results of the present study, therefore, can be considered not only typical of a single speaker but, in light of previous data, should be considered of more general reliability.…”

“…Another parameter that can be considered for speech rhythm description is the Vowel-to-Vowel index (VtoV), which corresponds to the average interval between two consecutive vowel onsets ( Pettorino et al, 2013 ). In fact, rhythm is linked to the recurrence of audible signal discontinuities.…”

Disfluency and speech management in Italian patients with early-stage Parkinson's Disease

“…The collected corpus was already the object of a rhythmical analysis in a previous work [20], which highlighted a comparable articulation rate in the two groups of speakers, calculated using the VtoV parameter, i.e., the mean duration of the intervals between two consecutive vowel onsets [21]: in the PD speech the mean VtoV value was 0,188 s, in healthy speech it was 0,185 s. Moreover, mean data on speech time composition showed no statistical difference in the percentage of disfluent time on the total utterance (PD= 14%; HC= 11%). Starting from these observations, a more in-depth analysis was conducted on disfluency phenomena.…”

Efeito do estilo de elocução e do falante sobre o tamanho mínimo de amostra para estimativa da taxa de produção da fala

“…Compreende os segmentos produzidos entre dois ataques vocálicos consecutivos. VerPettorino et al (2013) eBarbosa (2019, p. 40 e 55-60) para uma justificativa do uso das unidades VV no estudo de fenômenos prosódicos.…”