  On average the lack of biological markers causes a one year diagnostic delay
to detect amyotrophic lateral sclerosis (ALS). To improve the diagnostic
process an automatic voice assessment based on acoustic analysis can be used.
The purpose of this work was to verify the sutability of the sustain vowel
phonation test for automatic detection of patients with ALS. We proposed
enhanced procedure for separation of voice signal into fundamental periods that
requires for calculation of perturbation measurements (such as jitter and
shimmer). Also we proposed method for quantitative assessment of pathological
vibrato manifestations in sustain vowel phonation. The study's experiments show
that using the proposed acoustic analysis methods, the classifier based on
linear discriminant analysis attains 90.7\% accuracy with 86.7\% sensitivity
and 92.2\% specificity.
