The Effect of Speaking Style on the Articulatory-Acoustic Vowel Space in Individuals with Tongue Cancer before and after Surgical Treatment

The impact of surgical treatment for tongue cancer is traditionally assessed with vowel formant metrics from read speech or sustained vowels. However, isolated speech might not fully reflect a speaker's typical speech. Here, we assessed the effect of speaking style (read vs.~semi-spontaneous) on vowel acoustics of individuals pre- and post-surgery for tongue cancer. Eight individuals (3 females and 5 males) were recorded pre- and approximately six months post-surgery. We calculated the articulatory-acoustic vowel space (AAVS) during read speech (sentences) and semi-spontaneous speech (picture description). Results showed that the AAVS did not differ significantly pre- and post-surgery. Picture descriptions yielded a significantly smaller AAVS compared to the reading task, which was consistent pre- and post-surgery. Our findings suggest that both read and semi-spontaneous speech styles would be suitable to quantify the impact of surgical intervention for tongue cancer on vowel acoustics.