We investigated the change in hearing-health behaviour amongst teenagers trained to deliver the Dangerous Decibels programme to younger children. The Dangerous Decibels programme uses a two-stage process to train 8-12 year-old children to protect their hearing from noise: (1) a team of experts train 'Educators' who (2) give classroom training to children in schools. Training teenagers as Educators may add a second level of benefit if teenagers internalize the hearing-health messages that they present and thus protect their own hearing better. They were assessed before training, immediately after, and three months later (after all had presented the classroom training) using a questionnaire. In addition, a focus group was conducted with a subgroup of the Educators to assess their subjective experience. We trained 44 Educators aged 14-17 years. Results were generally positive: there were significant and sustained improvements in knowledge, self-reported behaviour, and perceived supports towards protecting hearing, and trends but not significant changes in attitudes or perceived barriers to hearing protection. Providing training to teenagers had benefits beyond the delivery of training to younger children, but improvements in the delivery model may increase the uptake and impact on the teenagers.