Diagnosing poor co-ordination between the Duke's larynx and thoracic diaphragm, Logue prescribed a daily hour of vocal exercises. Logue's treatment gave the Duke the confidence to relax and avoid tension-induced muscle spasms. As a result, he suffered only the occasional hesitancy in speech. By 1927, he was speaking confidently and managed his address at the opening of the Old Parliament House in Canberra without stammering.