  The low temperature dynamics of a vortex in a trapped quasi-two-dimensional
Bose-Einstein condensate are studied quantitatively. Precession of an
off-centred vortex in a dimple trap, embedded in a weaker harmonic trap, leads
to the emission of sound in a dipolar radiation pattern. Sound emission and
reabsorption can be controlled by varying the depth of the dimple. In a shallow
dimple, the power emitted is proportional to the vortex acceleration squared
over the precession frequency, whereas for a deep dimple, periodic sound
reabsorption stabilises the vortex against radiation-induced decay.
