The pilot had not flown for some time and was practicing circuits with her husband who was also a pilot. On downwind, her pre-landing checks were interrupted by a radio call. The aircraft was subsequently landed with the gear retracted. The gear warning horn was not serviceable prior to the flight. After the aircraft was established on final the pilot's husband commenced to stow the headsets and other loose items which were in the cockpit. He did not monitor the approach and therefore did not notice that the pilot had omitted to lower the landing gear.
