A systematic comparison of contemporary automatic speech recognition engines for conversational clinical speech

Conversations especially between a clinician and a patient are important sources of data to support clinical care. To date, clinicians act as the sensor to capture these data and record them in the medical record. Automatic speech recognition (ASR) engines have advanced to support continuous speech, to work independently of speaker and deliver continuously improving performance. Near human levels of performance have been reported for several ASR engines. We undertook a systematic comparison of selected ASRs for clinical conversational speech. Using audio recorded from unscripted clinical scenarios using two microphones, we evaluated eight ASR engines using word error rate (WER) and the precision, recall and F1 scores for concept extraction. We found a wide range of word errors across the ASR engines, with values ranging from 65% to 34%, all falling short of the rates achieved for other conversational speech. Recall for health concepts also ranged from 22% to 74%. Concept recall rates match or exceed expectations given measured word error rates suggesting that vocabulary is not the dominant issue.