This study has the aim to find out the data about the reflection of the neurological state in the voice features of infants and children. Two types of experiments were conducted: comparing of vocalizations of 0-3 months old infants having neurological disorders (n = 45) and typically developed (TD) infants (n = 50); comparison of speech features of TD children (n=30) with vocalization and speech features of 5-16 years old children with autism spectrum disorders (ASD) (n=30). The results of the study showed that the infant’s vocalizations contain features important for determination of the risks of development. Differences between children with ASD and TD on the basis of higher values of pitch, pitch variability and formant characteristics were revealed.