The crew of VH-FNB flew the aircraft into the circuit area intending to land on runway 06. They then sighted another aircraft on final for runway 24. Calls were made to the other aircraft on the area frequency and the Mandatory Traffic Advisory Frequency (MTAF). No reply was received. The crew of VH-FNB changed their approach to land on runway 24. The other aircraft made a touch and go landing on runway 24 and then made a radio call. A call from the crew of VH-FNB advised that they were on final approach for runway 24. Radio contact was established with VH-MUF, the other aircraft, and the pilot of VH-MUF advised he had previously had the volume on his radio turned down. Significant Factor The following factor was considered relevant to the development of the incident: 1. The pilot of VH-MUF was operating with the radio volume turned down.