The student was undertaking his fourth solo flight, and had been instructed to practice circuits with touch and go landings. After acknowledging a landing clearance, the pilot inadvertently dropped the microphone. He leant down to retrieve it, and shortly afterwards the aircraft touched down heavily about 200 metres in from the threshold. The aircraft bounced, the pilot applied forward elevator control, and a further heavy touchdown took place on the nosewheel and propeller. The nosegear folded back and the aircraft groundlooped to a halt on the flight strip. The student had become distracted from controlling the aircraft while attempting to retrieve the microphone. When he looked up again, he realised that the aircraft had deviated from the desired flight path, but he had persevered with the approach.