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Missing Jet Recordings May Have Been 'Edited': Experts (NBC NEWS)
Saturday 3 May 2014

Audio recordings of the final conversations between pilots of the missing Malaysian jet and teams of air traffic controllers on the ground were "edited" before they were made public, voice experts say.

The tapes also appear to be recorded by at least two different audio sources, one of which may have been a digital recorder held up to a speaker, they said.

The analysts cautioned that their observations don't necessarily imply anything about the investigation into the missing flight.

The quality and brevity of the interactions between the cockpit and controllers made it impossible to glean any information about the pilots' state of mind before the plane disappeared, or even to determine whether both the pilot and co-pilot were speaking or if just one can be heard.

The audio recordings were published Thursday for the first time as part of a preliminary report by Malaysian authorities . In the report, Malaysia's Air Accident Investigation Bureau said a lack of real-time tracking devices caused "significant difficulty" in the hunt for MH 370, which disappeared March 8.




Analysts who listened to the recordings for NBC News did not know why they were edited, but discovered at least four clear breaks in the audio that indicated edits.

"It's very strange," said audio-video forensic expert and registered investigator Ed Primeau of Primeau Forensics, who has analyzed hundreds of audio recordings. He said the beginning and end of the recording are high-quality with a low noise floor, meaning ambient background noise is almost silent, unlike the middle.

"At approximately 1:14 (a minute, 14 seconds into the audio, which can be heard here ), the tone of the recording change to where to me, it sounds like someone is holding a digital recorder up to a speaker, so it's a microphone-to-speaker transfer of that information. That's a pretty big deal because it raises the first red flag about there possibly being some editing," he said.

The next part that raises questions is two minutes, six seconds in, through two minutes, nine seconds in, he said.

"I can hear noise in the room, along with the increase in the noise floor. I can hear a file door being closed, I can hear some papers being shuffled. so I'm further convinced that, beginning at 1:14 continuing through 2:06 to 2:15, it's a digital recorder being held up to a speaker."

Long gaps in the communication throughout the recording also imply some editing, he said.

"But yet, at 6:17, there's a huge edit because the conversation is cut off. It's interrupted. And the tone changes again," he said. "The noise floor, when you're authenticating a recording from a forensic perspective, is a very important part of the process. All of a sudden, we go back to the same quality and extremely low noise floor that we had at the beginning of the recording."

Kent Gibson, a forensic audio examiner with Forensic Audio in Los Angeles, added that there appear to be additional edits at 2:11 and 5:08, and agreed it sounded as though the middle section was recorded with a microphone near a speaker.

"You can hear, at 4:07, pages turning or a person breathing, which is unusual," he said.

While it's not uncommon for the background of a recording to change when a cockpit communication turns over from ground control to air controllers which happened about four minutes into this recording that doesn't explain the noises that are heard.

"It's not unusual that there would be clicks when they push the button on the microphone, but it's very unusual to have a disturbance. Normally you wouldn't have any background," Gibson said.

A cut-off word also isn't out of the realm of possibility, he said.

"It wouldn't be unthinkable to have a truncated word because if somebody let go of the trigger on the microphone, it might cut off their word," he said. "But it would be very unusual to find a background differential at the same time, suggesting that Malaysian authorities or whoever presented this made edits for whatever reason."

Gibson said it's possible the tapes could have been edited by Malaysian authorities "if the pilot dropped a hint that they didn't want to get out, if he said something that doesn't fit with the Malaysian government's party line."

But, he said, "It's more likely to be an inadvertent thing. But it's not the way to handle evidence."

The recording also could have come from different sources, he added.

"You can assume that the recording while they're still on the ground came from the tower and then you could assume that the communication with air controllers was while they're in the air," he said. "They may have just mishandled the cobbling of it together."

This doesn't necessarily prove anything about the investigation, he added.

"Unfortunately, there are no smoking guns, except there are edits. And there are clear edits," he said.

Tom Owen, a consultant for Owen Forensic Services audio analysis and chairman emeritus of the American Board of Recorded Evidence, said edits were to be expected.

"There's things that have to do with timelines and radar that they have available, but they don't make them available," he said. "They wouldn't give you anything that would be enlightening for the public to any secretive information. I don't see that as a problematic issue."

Primeau disagreed.

"This is not a good maneuver or a good faith move by the Malaysian government because of all these questions with regard to the different anomalies and edits that are in this recording," he said.

Audio experts felt the quality of the transmissions was too low to offer analysis of the pilots' voices.

Forensic audio expert Paul Ginsberg said even after enhancing and slowing down the conversations, there wasn't good enough, or long enough, sound samples to make a determination on the pilots' stress level.

"It's analogous to blowing up a photograph. It's the same amount of information," he said. "I don't know that any such determination would be admissible."

(NBC News)

ps. sources linked by Bookofresearch



Published 1 May 2014: The Malaysian government finally released a recording today with their report of the conversation between Malaysian Flight 370 and Air Traffic Control. I had the opportunity to listen to the recording and have several concerns from an audio forensic perspective.

Read the full article HERE:



Comment of bookofresearch On expert analyzes of audio recordings: Missing Jet Recordings May Have Been 'Edited': Experts (NBC NEWS)


Below statement and attached documents were made public and shared with NOKs at 8:27pm (Malaysia local time), 1 May 2014: 


  1. 1. ATC Delivery (wav)
  2. 2. KL Ground (mp3)
  3. 3. KL Tower (mp3)
  4. 4. KL Approach (mp3)
  5. 5. KL Radar (wav)
  6. Actions taken between 0138 and 0614
  7. Cargo Manifest and Airway Bill
  8. Maps
  9. Preliminary Report
  10. Seating plan


a. The audio recordings consist of five files which should be listened to in sequence.

b. The attached map shows MH370's flight path, based on the best available knowledge of the investigation team. There are a number of possible flight paths to the southern Indian Ocean, and three boxes indicating where MH370 likely ended. These flight paths differ based on different projections of the aircraft's speed, shown on the map in knots.

c. The attached preliminary report was drafted with the involvement of the NTSB, AAIB, ATSB, AAID and CAAC, as well as Malaysian officials.


An overview of the preliminary files here

The release of the preliminary files were first posted on the Facebook page of Minister of Defence & Acting Minister of Transport Hishammuddin Hussein and announced via his twitter account:


The Statement given with the released files cleary notes:



a. The audio recordings consist of five files which should be listened to in sequence.


Here the statement and the five audio recording files:


  1. 1. ATC Delivery (wav) 01min:11sec
  2. 2. KL Ground (mp3) 3min:59secs
  3. 3. KL Tower (mp3) 41secs
  4. 4. KL Approach (mp3) 25secs
  5. 5. KL Radar (wav) 48secs
Total time audio recordings: 6min:24secs
Total time Youtube video: 07min:10secs

ps. From an earlier releasement:

Audio Transcript MH370 Pilot-ATC BIT.pdf Release date: 1 April 2014
Part 1
Part 2
Starts at 12:25:53 and Ends at 01:19:29, a total time of 54 min and 36 secs between airtraffic control and cockpit.
    From   Total time
1. ATC DELI VERY   12:25:52 - 12:26:55   01min:03secs
2. LUMPUR GROUND   12:27:27 - (12:36:19 +)   approx 8min:52sec +
3. LUMPUR TOWER   12:36:30 - (12:40:38 +)   approx 4min8sec +
4. LUMPUR APPROACH   12:42:05 - (12:42:52 +)   approx 47sec +
5. LUMPUR RADAR (AREA)   12:46:51 - 01:19:29   32min:38sec
Note: + is latest time given, not end time, so total time is also +
More documents: here


The released youtube video contains an audiofile in one piece.

On Malaysian Airlines website, Statement 29, the files were released the same day (may 1, 2014) in pdf's and the audiofile as downloads in five pieces.
Their formats are, in the following order; a wav file, an mp3 file, an mp3 file, an mp3 file and another wav file. (as highlighted above)

The 'editing' that NBC News 'experts' have discovered; '4 clear breaks and differences in sound and background noise' could have been caused by the audio files being released as the five files mounted to one, in a video.

* Mounting five files to one file gives four breaks.

wav | mp3 | mp3 | mp3 | wav

* Also note that WAV files and mp3 files are very different files which differ in sound, processing and format.

* Both can be done for research reasons / part of the investigation (splitting a file and using different formats)

Here's a summary of the differences between wav & mp3 files:

WAV files

A WAV file is a very simple, accurate, lossless format, which nowadays can achieve astonishingly high recording rates with huge dynamic ranges.
As a result of the files simplicity, wav files are relatively easy to process and edit. wav's are an excellent format to work in for studio recordings, mastering, and pro-audio applications.

WAV files are large. A stereo, CD quality recording (44.1khz, 16-bit), works out at 10.09 MB per minute. Moving up to 48kHz 24-bit stereo, which improves both the frequency range and the available dynamic range, but will increase the file size to 16.48 MB per minute. The large file size of WAV's makes them impractical for portable devices and streaming.

MP3 Files

Unlike WAV files, MP3s are a lossy format. This means that encoding audio to MP3 will reduce its quality, but also reduces its file size. It is the manner in which it achieves this that makes it so clever.

The scientific study of how people perceive sound is named Psychoacoustics. There are many anomalies in the way we hear. It is these quirks in our hearing that are exploited by MP3 files. There are certain frequencies our ears can not hear or are too loud. The way in which an MP3 encodes, it masks the loud sounds and gets rid of the 'hidden' data.

MP3 files are compressed files with little perceivable difference to the overall sound quality. The file size is small and can be easily distributed over the internet, computers and handheld devices.


- The experts likely based their analyzes on the file released in the youtube video

- The total time of the youtube video is 07 min and 10 secs

- The total time of the five audio recordings that have been released is 6 min and 24 secs

1. ATC Delivery (wav)   01min:11sec
2. KL Ground (mp3)   3min:59secs
3. KL Tower (mp3)   41secs
4. KL Approach (mp3)   25secs
5. KL Radar (wav)   48secs

- There's a difference of 46 secs between the total time of the youtube video and the total time of the five released audio recordings

- The audio transcript starts at 12:25:53 and ends at 01:19:29 a total time of 54 min and 36 secs between airtraffic control and cockpit.

    From   Total time
1. ATC DELI VERY   12:25:52 - 12:26:55   01min:03secs
2. LUMPUR GROUND   12:27:27 - (12:36:19 +)   approx 8min:52sec +
3. LUMPUR TOWER   12:36:30 - (12:40:38 +)   approx 4min8sec +
4. LUMPUR APPROACH   12:42:05 - (12:42:52 +)   approx 47sec +
5. LUMPUR RADAR (AREA)   12:46:51 - 01:19:29   32min:38sec
Note: + is latest time given, not end time, so total time is also +

- Only parts of the audio recordings have been released

May 5 2014: Why are there two different file formats (wav & mp3) released and mounted to one in the released video, and why are there only parts of the full audio file released. The answer could solve the speculations





- What investigators can learn from MH370 Radio Communications and Cockpit Voice Recorder (ProAudioLabs)
- Archive Audio Files WMKK Lumpur Control LiveATC.net - Archives only kept for 30 days (also note date/time is in GMT/UTC) Files MH370 are no longer there
1 May 2014: Malaysia Airlines Flight MH370 Airtraffic communications is edited (ForensicExperts)
3 May 2014: Missing Jet Recordings May Have Been 'Edited': Experts (NBC NEWS)
5 May 2014: MH370: No info on audio tampering, says Hishammuddin (Astro Awaini)



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