Beware of the individual: Evaluating prominence perception in spontaneous speech

Much of the existing research on prominence perception has focused on read speech in American English and German. The present paper presents two experiments that build on and extend insights from these studies in two ways. Firstly, we elicit prominence judgments on spontaneous speech. Secondly, we investigate gradient rather than binary prominence judgments by introducing a finger tapping task. We then provide a within-participant comparison of gradient prominence results with binary prominence judgments to evaluate their correspondence. Our results show that participants exhibit different success rates in tapping the prominence pattern of spontaneous data, but generally tapping results correlate well with binary prominence judgments within individuals. Random forest analyses of the acoustic parameters involved show that pitch accentuation and duration play important roles in both binary judgments and prominence tapping patterns. We can also confirm earlier findings from read speech that differences exist between participants in the relative importance rankings of various signal and systematic properties.