Jakarta: Warning alarms in AirAsia flight QZ8501 were "screaming" as the pilots desperately tried to stabilise the plane just before it plunged into the Java Sea last month, a crash investigator says.

The noise of several alarms - including one that indicated the plane was stalling - can be heard going off in recordings from the black box in the Airbus A320-200's cockpit, the investigator told AFP, requesting anonymity.

"The warning alarms, we can say, were screaming, while in the background they [the pilot and co-pilot] were busy trying to recover," the investigator said on Wednesday, adding the warnings were going off "for some time".

The investigator, from Indonesia's National Transportation Safety Committee, said the pilots' voices were drowned out by the sound of the alarms.