Automatic quantification of speech intelligibility in patients after treatment for oral squamous cell carcinoma.

PURPOSE: Treatment of oral carcinomas often causes reduced speech intelligibility. It was the aim of this study to objectively evaluate the speech intelligibility of patients after multimodal therapy for oral squamous cell carcinoma (OSCC) with a computer-based, automatic speech recognition system.

MATERIALS AND METHODS: The speech intelligibility of 59 patients after multimodal tumor treatment for OSCC, located at the lateral tongue, floor of the mouth, or the alveolar crest of the lower jaw, was objectively analyzed by a computer-based speech recognition system that calculates the percentage of correct word recognition (WR).

RESULTS: The patients' WR was significantly reduced compared with a healthy control group without speech impairment (P ≤ .001). Higher T-classification was associated with a reduced WR (P < .01). Tumors located at the tongue showed a significantly higher WR than tumors at the floor of the mouth or the alveolar crest (P ≤ .001). Surgical resection and reconstruction of the lower jaw bone significantly reduced the WR (P ≤ .001) compared with cases without osseous tumor infiltration.

CONCLUSIONS: Speech intelligibility after treatment for OSCC, objectively quantified by a standardized automatic speech recognition system, is reduced for increasing tumor size, increasing resection volume, and tumor localization near the lower jaw. Surgical reconstruction techniques seem to have an impact on speech intelligibility.