The Lombard Effect On Speech Clarity In Patients With Parkinson Disease

Download or read book The Lombard Effect on Speech Clarity in Patients with Parkinson Disease written by Firas Saler Daher Alfwaress and published by . This book was released on 2008 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vocal loudness tends to increase when healthy speakers are speaking in the presence of background noise. Acoustic studies of Lombard speech have shown that other articulatory changes associated with increased intelligibility occur along with the increase in loudness. Lombard speech in healthy speakers is characterized by decreased speaking rate, increased fundamental frequency range and mean, as well as increased vowel space. These results suggest a more complex interaction between auditory monitoring of speech and motor speech planning in this uncommon speaking environment. Recently, there has been increased interest in the effect of background noise on speakers with Parkinson Disease (PD). In this study, nineteen patients with Mild-to-Moderate Idiopathic PD (10 males and 9 females) and 19 age-and-sex matched healthy speakers were recruited to investigate these acoustic-phonetic measures in quiet and in Lombard conditions. A 90 dB SPL noise was given binaurally via a closed headset to induce the LE. Subjects were engaged in repeating the syllable chain /pataka/ and reading a set of phonetically balanced sentences. Speaking rate was measured by the diadochokinetic (DDK) task and speech rate (SR). Vocal loudness measures included intensity (INT) and intensity standard deviation (INTSD). Fundamental frequency range (F0Rge), mean (F0M), and standard deviation (F0SD) were the acoustic measures of fundamental frequency. The vowel space (VS) was obtained by measuring the vowel quadrilateral of the corner vowels /i, æ, a, u/ in the vocal tract. Repeated measures ANOVA results showed a statistically significant increase in vocal loudness measures, increase in F0 measures, and a decrease in speaking rate measures in both groups as a function of noise. The VS was not statistically different for both groups of participants in the Lombard condition. The male speakers in both groups showed increased VS compared to their female counterparts. The Parkinsonian group showed a smaller VS area in both conditions. In particular, the PD patients with moderate severity showed centralized VS compared to the healthy participants. These findings suggest that speakers with PD utilize neuromotor planning for speech production with the same capacity as non-impaired speakers; however, this capacity tends to deteriorate as PD becomes advanced.