Towards automatic assessment of aphasia speech using automatic speech recognition techniques

Aphasia is a type of acquired language impairment caused by brain injury. This paper presents an automatic speech recognition (ASR) based approach to objective assessment of aphasia patients. A dedicated ASR system is developed to facilitate acoustical and linguistic analysis of Cantonese aphasia speech. The acoustic models and the language models are trained with domain- and style-matched speech data from unimpaired control speakers. The speech recognition performance of this system is evaluated on natural oral discourses from patients with various types of aphasia. We analyze the recognition outputs for a set of selected utterances in the aspects of supra-segmental duration and linguistic content, and confirm the effectiveness of the relevant features in the assessment of aphasia speech.