Adrian Underhill is a British teacher trainer, writer, and jazz musician, best known to the ELT profession for his work on pronunciation and, later, Demand-High Teaching. Long associated with International House and the Hastings-based International Teacher Training Institute, he has been a regular plenary speaker at IATEFL and similar conferences for decades.
Underhill's signature contribution is the interactive phonemic chart and the pronunciation pedagogy around it, developed across successive editions of Sound Foundations. His approach treats pronunciation as a physical, discoverable, muscular subject rather than a list of contrasts to memorize. With Jim Scrivener, he launched Demand-High Teaching, a movement pushing back against the low-challenge tendencies of routine communicative classrooms.