This study examines the effects of spoken-voice intervention on students’ vocal performance in relation to the delivery of interpreting. This study adopted a mixed-method design with both quantitative and qualitative approaches in the description of learners’ performance. The data analysis shows that the spoken-voice intervention groups recorded significantly higher levels of vocal performance than the non-intervention group. This study concluded that the spoken-voice intervention approach yielded a highly positive intervention outcome, resulting in significant levels of improvement in vocal performance in relation to the delivery of interpreting delivery for the 3 intervention groups.