The effect of speech pathology on automatic speaker verification -- a large-scale study

With the advancements in deep learning (DL) and an increasing interest in data-driven speech processing methods, there is a major challenge in accessing pathological speech data. Public challenge data offers a potential remedy for this but may expose patient health information by re-identification attacks. Therefore, we investigate in this study whether or not pathological speech is more vulnerable to such re-identification than healthy speech. Our study is the first large-scale investigation on the effects of different speech pathology on automatic speaker verification (ASV) using a real-world pathological speech corpus of more than 2,000 test subjects with various speech and voice disorders from different ages. Utilizing a DL-based ASV method, we obtained a mean equal error rate (EER) of 0.89% with a standard deviation of 0.06%, which is a factor of three lower than comparable healthy speech databases. We further perform detailed analyses of external influencing factors on ASV such as age, pathology, recording environment, utterance length, and intelligibility, to explore their respective effect. Our experiments indicate that some types of speech pathology, in particular dysphonia, regardless of speech intelligibility, are more vulnerable to a breach of privacy compared to healthy speech. We also observe that the effect of pathology lies in the range of other factors, such as age, microphone, and recording environment.