Acoustic analysis of changes in articulation proficiency in patients with advanced head and neck cancer treated with chemoradiotherapy.

Objectives: Our aim was to characterize articulation proficiency and differences between tumor sites before and after chemoradiotherapy for advanced head and neck cancer with the help of acoustic measures. Our further goal was to improve objective speech measures and gain insight into muscle functioning before and after treatment.

Methods: In 34 patients with laryngeal or hypopharyngeal, nasal or nasopharyngeal, or oral or oropharyngeal cancer, we acoustically analyzed nasality, vowel space, precision, and strength of articulation in 12 speech sounds (/a/, /i/, /u/, /p/, /s/, /z/, /1/, /t/, /tj/, /k/, /x/, /r/) before treatment and 10 weeks and 1 year after treatment. Outcomes were compared between assessment points and between tumor sites.

Results: Nasality in nonlaryngeal sites was significantly reduced by treatment. Most affected in articulation were the oral or oropharyngeal cancer sites, followed by the nasal or nasopharyngeal sites. One year after treatment, vowel space had not recovered and consonant articulation had weakened. Laryngeal sites were less affected in articulation by tumor or treatment.

Conclusions: Analyses of articulatory-acoustic features are a useful instrument for assessing articulation and speech quality objectively. Assessment of a number of sounds representing various articulation manners, places, and tongue shapes revealed patterns of speech deterioration after chemoradiotherapy. The results suggest that patients' speech could benefit from articulation exercises to address changes in muscle coordination and/or sensitivity and to counteract side effects and "underexercise" atrophy.