Articulatory clarity and variability before and after surgery for tongue cancer

TL;DR

This study examines how tongue cancer surgery affects speech clarity and variability, finding that clarity remains within normal ranges but variability increases post-surgery.

Contribution

It provides new insights into articulatory changes after tongue cancer surgery using VAI and VFD measures in a longitudinal study.

Findings

Articulatory clarity (VAI) decreases post-surgery but remains within typical ranges.

Articulatory variability (VFD) increases for certain vowels after surgery.

No significant difference in clarity between patients post-surgery and typical speakers.

Abstract

Surgical treatment for tongue cancer can negatively affect the mobility and musculature of the tongue, which can influence articulatory clarity and variability. In this study, we investigated articulatory clarity through the vowel articulation index (VAI) and variability through vowel formant dispersion (VFD). Using a sentence reading task, we assessed 11 individuals pre and six months post tongue cancer surgery, alongside 11 sex- and age matched typical speakers. Our results show that while the VAI was significantly smaller post-surgery compared to pre-surgery, there was no significant difference between patients and typical speakers at either time point. Post-surgery, speakers had higher VFD values for /i/ compared to pre-surgery and typical speakers, signalling higher variability. Taken together, our results suggest that while articulatory clarity remained within typical ranges following surgery for tongue cancer for the speakers in our study, articulatory variability increased.