![]() ![]() ![]() 87 (PRAAT) for measures of jitter, with lower correlations among measures of shimmer. For the normal data, r Pearson correlations ranged from. Parameters related with shimmer were more reliable than parameters related with jitter. Results demonstrate that the reliability of the values obtained by both programs was significantly reduced with the increase of irregularities in the signal. The empirical evidence shows that if followed the default values and thresholds of each system, the diagnostic accuracy might be questioned by considering both cases as false positives or false negatives. However, the values of jitter, shimmer and harmonic-to-noise ratio (HNR) were significantly lower measured by PRAAT, and higher using ANAGRAF in relation which the default results proposed by each system. ![]() For both programs the results show similar values of fundamental frequency (F0). The test-retest reliability in each pair of measures was calculated. ![]() The findings of analyzed voice samples are showed by definitions for mean, standard deviation, and thresholds of normal for each parameter, which helps the clinician to immediately assess the findings for a particular patient. General results separated by sex are reported. The parameters with normal distribution had their means compared to the standard measurements proposed by the program using the t test (significance level of 5%). The Lilliefords Test, with a significance level of 5%, was used to verify the normal distribution of the results of each measurement. A total of 776 voice samples corresponding to 4 repetitions of the vowel /a/ of 194 speakers of Spanish in Buenos Aires were measured using the available parameters such as: the fundamental frequency, jitter, shimmer, and noise-to harmonic ratio. The purpose of this work was to compare the results obtained by a set of acoustic parameters, many of which are defined similarly in both programs, and analyze whether it can distinguish clinically between normal and pathological voices within different severity levels. PRAAT, was designed by Boersma and Weenink (2009) and ANAGRAF is a national software designed by Gurlekian (1997). Both systems are computer programs commonly used in Latin America, in clinical and research to detect and characterize speech and voice disorders. In this study, acoustic analysis was performed using two different programs: PRAAT and ANAGRAF. Little formal information is available about the actual comparability of measures from different analysis packages. Furthermore, product documentation often makes it difficult to know how a particular system actually produces its measurements. However, there is no standardization of technique methodology and considerable variability is observed about which acoustic parameters must be measured. The fact of using the same labels for similar measurement output like mean jitter or mean shimmer induce to think that results from different programs are comparable. Those systems packages are presented as objective tools with apparently standardized, well-designed measurement protocols and acceptably low incidence of technical problems. Acoustics measures of vocal productions received much attention in the literature and a variety of commercial packages are available. The need for instrumental objective assessment of voice quality is reflected in the increasing number of acoustic analysis methods developed for clinical diagnosis and as research outcome in the area. Acoustic analysis of normal and pathological voices using two different systems: ANAGRAF and PRAAT. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |