Speech quality after major surgery of the oral cavity and oropharynx with microvascular soft tissue reconstruction

Speech quality of patients with oral or oropharyngeal carcinoma was assessed by perceptual and acoustic-phonetic analyses. Speech recordings of running speech of patients before and 6 and 12 months after treatment for oral or oropharyngeal cancer and of 18 control speakers were evaluated regarding intelligibility, nasality and articulation, which revealed deteriorated speech in 20% of the patients before treatment, and in 75% 6-12 months after treatment. Acoustic analyses comprised formant, duration, perturbation and noise measures of the vowels /i/, /a/, and /u/ and were performed on the speech samples 6 months after treatment and the controls. Patients appeared to have a smaller vowel space compared to controls, which was clearly related to speech intelligibility. Furthermore, voice perturbation appeared to be higher in patients. Although oropharyngeal treatment does not effect the function of the larynx itself, the acoustic coupling between source and filter may effect the smoothness of the voicing characteristics. The presented speech analyses may serve as part of an outcome measurement protocol for assessing efficacy of speech rehabilitation.