Background and objectives: Oral squamous cell carcinoma (OSCC) and its treatment impair speech intelligibility. It was the aim of this study to objectively analyse the speech intelligibility of patients before and after therapy for OSCC by an automatic, computer-based speech-recognition-systems (ASR).
Methods: Speech intelligibility from 83 patients (mean age: 59 ± 35/84) with OSCC was analysed before as well as 1, 3, 6 and 12 month after surgical therapy by an ASR according to the word recognition rate (WR). Reconstruction (local flap/free flap) and adjuvant radiotherapy were conducted according to the defect and the tumour stage. Speech data of the patients were compared to a healthy reference population.
Results: WR before resection was significantly reduced in all OSC patients (WR 62% ± 14) compared to reference group. WR was lowest after tumour resection (WR 37 ± 17) with a melioration towards the 12 month post treatment data which yielded an average intelligibility reduction of 15%, compared to the pre-therapeutic results ( p < 0.05) and of 25% compared to the reference group ( p < 0.05).
Conclusions: OSCC and its therapy are coming with a reduction of speech intelligibility, objectifiable by ASR in a standardized way. T-stage, localization, resection-volume and radiotherapy are crucial factors for speech intelligibility.