six is the number of 747 solo inflight breakups
The Aloha 737 CVR tape would be of interest. So would the United Airlines Flight 811 CVR tape and both are unavailable for analysis for sounds.
Some of your questions have been examined in detail in other Boeing 747 inflight breakup AARs.
Hull rupture in flight: Air India Flight 182
Below are from CASB AAR for AI 182 and note that although the best evidence, the CVR, reveals no bomb explosion, the conclusion of the media and the RCMP is bomb and three are on trial for blowing the plane up.
Also note match of the pressurization warning sound of DC 10 which may match the ‘altitude alert’ sound for China Airlines Flight 611.
Note match of comment of ‘human cry’ on Air India Flight 182 and the ‘groan’ and ‘heartbeats’ for China Airlines Flight 611.
“07:27:38 CAM (sound similar to altitude alert)” for China Airlines Flight 611
From Air India Flight 182 AAR:
“On the DC-10, the pressurization audio warning sounded 2.2 seconds after the decompression.
The AIB report concluded that the analysis of the CVR and ATC recordings showed no evidence of a high-explosive device having been detonated on AI 182.
3.4.6.7 Mr. B. Caiger's Report and Deposition
Mr. Caiger has said in his report that the Cockpit Area Microphone signal was studied in detail. According to him, in an aircraft, sound can be transmitted by multiplicity of paths. If an explosive device was located close to the microphone then the short wave from the disturbance would cause a sharp rise in pressure which was not noticed. From more remote location, however, structurally transmitted sounds could reach the microphone first and induce more complex signals. According to Mr. Caiger, at this time he did not have any evidence from occurrences of this nature that would permit any meaningful comparisons or conclusions.
"Listening to the sounds, it also appears that a human cry occurs near the end of the recordings. Spectral analysis of these sounds and comparison with voice limitations reveals that the accident sounds do not contain all the pitch harmonic frequencies normally associated with such voice sounds. The origin of all the sounds has not been identified."
3.4.6.16 In conclusion, Mr. Davis reported as follows :-
"It is considered that from the CVR and ATC recordings supplied for analysis, there is no evidence of a high explosive device having detonated on AI 182.
"There is strong evidence to suggest that a sudden explosive decompression occurred but the cause has not been identified.
"Although there is no evidence of a high-explosive device, the possibility cannot be ruled out that a detonation occurred in a location remote from the flight deck and was not detected on the microphone. Such a situation would be most unusual, if not unique, in that we have never failed to detect sounds of structural failure, decompression, explosives etc., on any accident CVR, even though the event occurred at the rear of the aircraft. If such a device was used on AI 182 it is considered that it would have to be a very small device in order not to be detected (unlikely in itself). Such a device would be unlikely to cause the sudden total destruction which occurred in this instance. It is considered that a device of sufficient power to produce this effect could not fail to be detected on the CVR. The B-747 explosions referred to earlier, blew holes several feet wide in the structure but the crew were still able to control and operate the aircraft.”