Acoustic analysis of the speech of patients with oral cancer: A methodological investigation comparing speech stimuli derived from different clinical outcome measures

Abstract

Background: Oral cavity cancer and its treatment reduce the quality of speech. Clinicians often utilize a variety of outcomes measures to assess speech function of patients with oral cavity cancer reducing the comparability of formant results due to differences in linguistics and phonetic contexts. Objective: To evaluate the degree of agreement in vowel space size in a F1-F2 plane, when comparing speech stimuli selected from a controlled environment (i.e., /hVd/ context) to speech stimuli segmented from two clinically available speech outcome measures in patients treated for cancer of the oral tongue. Methods: Voice recordings of nine patients treated with primary surgery for cancer of the oral cavity who attended functional assessment appointments (pre-operatively, and at 1-, 6-, and 12-months post-operatively) were analyzed. Agreement between vowel space size obtained from /hVd/ phrases and other speech assessments were compared using linear correlations and t-tests. Results: Vowel space size derived from /hVd/ phrases correlates strongly with corresponding estimates from other speech tasks (r = 0.72 to 0.82, p <0.0001). The other tasks had significantly reduced vowel space sizes compared to /hVd/ (t = 4.7 to 5, p<0.0001). Conclusion: Vowel space size estimates based on different speech tasks are mutually comparable and may offer insight to oral cancer speech production acoustics.