Axions are hypothesised ultra-light particles that, if shown to exist, might both solve the dark matter problem and explain the apparent CP (charge conjugation and parity) symmetry of quantum chromodynamics, the theory of quarks. With the ever-more-stringent limits on new physics at the electroweak scale, the search for axions and other hidden sector fields has seen a worldwide resurgence of interest, including here in the UK. I will describe the ADMX resonant cavity axion search and present its recent results. I will also address the issue of the search rate for QCD axions with Sikivie-type resonant detectors of which ADMX is the most sensitive to date. I will describe an idea to use resonant feedback circuits to induce artificial resonances which, if successful, may increase the search rate for such experiments by factors of order 100.