In May 1925 the Oxford production of "The Cherry Orchard" was brought to the Lyric Theatre, Hammersmith. Gielgud again played Trofimov. His distinctive speaking voice attracted attention and led to work for BBC Radio, which his biographer Sheridan Morley calls "a medium he made his own for seventy years". In the same year Noël Coward chose Gielgud as his understudy in his play "The Vortex". For the last month of the West End run Gielgud took over Coward's role of Nicky Lancaster, the drug-addicted son of a nymphomaniac mother. It was in Gielgud's words "a highly-strung, nervous, hysterical part which depended a lot upon emotion". He found it tiring to play because he had not yet learned how to pace himself, but he thought it "a thrilling engagement because it led to so many great things afterwards".