Residual signal auto-correlation to evaluate speech in Parkinson's disease patients.
OBJECTIVE
To evaluate the maximum residual signal auto-correlation also known as pitch amplitude (PA) values in patients with Parkinson's disease (PD) patients.


METHODS
The signals of 21 Parkinson's patients were compared with 15 healthy individuals, divided according age and gender.


RESULTS
Statistical difference was seen between groups for PA, 0.39 for controls and 0.25 for PD. Normal value threshold was set as 0.3; (p<0.001). In the Parkinson's group 80.77%, and in the control group only 12.28%, had a PA<0.3 demonstrating an association between these variables. The dispersion diagram for age and PA for PD individuals showed p=0.01 and r=0.54. There was no significant difference in relation to gender and PA between groups.


CONCLUSIONS
The significant differences in pitchs amplitude between PD patients and healthy individuals demonstrate the methods specificity. The results showed the need of prospective controlled studies to improve the use and indications of residual signal auto-correlation to evaluate speech in PD patients.
Pereira
José Carlos
JC
School of Engineering of São Carlos, University of São Paulo.
Schelp
Arthur Oscar
AO
Montagnoli
Arlindo Neto
AN
Gatto
Ana Rita
AR
Spadotto
André Augusto
AA
de Carvalho
Lídia Raquel
LR
D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000503:physiopathology*; D010699:Phonation / Q000502:physiology*; D012680:Sensitivity and Specificity; D013018:Sound Spectrography; D013061:Speech Acoustics; D013064:Speech Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D013067:Speech Perception / Q000502:physiology; D013068:Speech Production Measurement; D014833:Voice Quality