Relative spectral and frication-based descriptors as numerical indicators of place of articulation shifts in fricatives produced by Polish children.

BACKGROUND AND

OBJECTIVE

The paper undertakes the topic of acoustic differences between normative and pathological articulation patterns in children. The analysis aimed to explore the impact of the place of articulation on the values of speech signal features in alveolar fricatives / , /.

METHODS

Normative (alveolar) pronunciation was compared to three atypical patterns: postalveolar, dental, and interdental. The presented analysis was conducted on our team's dataset of annotated productions collected from 187 preschool-aged children, the largest sample reported to date for the acoustic analysis of pathological child speech. The statistical significance of the differences was assessed using linear mixed-effects models, which account for inter-speaker dependencies in the acoustic data.

RESULTS

Our results show that newly introduced relational spectral descriptors, together with noise-energy subbands, reliably capture subtle distinctions among articulatory patterns, whereas fricative formant-level ratios effectively isolate tongue-position effects from voicing.

CONCLUSIONS

The study contributes to the field of computer-assisted speech diagnosis by identifying acoustic features to inform future tools dedicated for sigmatism analysis in children.