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Posts Tagged ‘Audio restoration’

JFK Assassination: Fully restored Air Force One recordings from November 22, 1963

Tuesday, November 19th, 2013

John F Kennedy At the end of this blog post is a fully restored digital audio file available for listening and downloading of the government conversation that occurred at the time of the assassination of President John F. Kennedy. The Announcer at the beginning of the recording  is the poorest quality of the entire 2:01:59.

This is a combination merged from two copies that were in existence. The first copy was released by the government and referred to as the ‘LBJ tapes’ in the early 1970’s. Another longer copy surfaced in a Philadelphia private auction in 2011. This longer copy was found in the belongings of the late General Clifton. Thanks to Bill Kelly, a veteran JFK researcher, Primeau Forensics has combined the contents of both recordings and fully restored them.

In this enhanced recording, you will hear conversations from Air Force One over the Pacific Ocean as they abort a trip to Japan and turn around, mid-air, to return to the mainland after learning about the assassination of the President of the United States. These recorded conversations between Ground Command, the White House and Air Force One include code names such as ‘Duplex,’ ‘Digest,’ ‘Volunteer,’ ‘Liberty,’ ‘Witness,’ ‘Crown,’ ‘Baker,’ ‘Watchman,’ and ‘Tiger.’

During the call they make arrangements to transport John F. Kennedy’s body, his widow, President Johnson and the other 40 people safely back to Washington DC. The carefully coordinated and strategically executed planning is heard in this recording. Decisions about media coordination on the ground at the White House, the post-mortem autopsy to be performed by law and President Johnson’s conversation with JFK’s mother, Rose Kennedy can also be heard.

It may take a while to get your ears acclimated to this early, mobile technology. Primeau Forensics has carefully removed unnecessary radio static and squeals to accommodate better listening. It is recommended that you use a combination of speakers and headphones to best listen to these recordings.

Listen to the updated Clarified Audio Track HERE:

[audio:http://www.primeauproductions.org/primeauforensics/JFK Airforce One Primeau Forensics .mp3|titles=JFK AIR FORCE 1 CLARIFIED AUDIO UPDATE]

Download Recordings Here!

Download Transcript Here!

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Air Force One Audio Restoration/Enhancement Process

Friday, November 15th, 2013

Air Force OneA lot of people have been asking how I restored the Air Force One radio transmissions from November 22 1963, right after JFK was shot. Below I have outlined my process with brief explanations about each.

I used a software program from Adobe CS 6 ‘Audition’ for this entire process.

I identified the points in each version of the tape recordings, the LBJ version and the General Clifton version, for edit points before altering the recordings for enhancement.

I began the restoration process by sampling the tape hiss present on the entire recording and reducing with Adobe noise reduction. Next I went section by section and reduced the radio transmission noise which varied from conversation to conversation.

Then I applied equalization and compression filtering to help bring out the conversations. This was also done section by section since each conversation varied in speaking frequencies.  Adobe CS6 has a great tool, the FFT equalization which is very easy to use.

Audio restoration and enhancement is a process. I refer to it as peeling an onion; one layer at a time. If something does not sound right, I go back a step and try a different process. That’s the beauty of digital audio restoration and enhancement.

I am still working on the restoration as time permits and will update the videos posted here. I am hearing more and more of the conversations using critical listening and additional enhancement. Considering how primitive the technology was back then I am very impressed with the sound quality of these recordings. By the way, the General Clifton version is much better sounding and longer then the LBJ version.

Read about how this all started, and you can watch the story on “The Lead” with Jake Tapper on CNN below.

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Primeau Forensics Restored Air Force One Recordings from John F. Kennedy Assassination

Tuesday, October 8th, 2013




Passing the Torch-An International Symposium on the 50th Anniversary of the Assassination of President John F. Kennedy will be happening October 17-19 2013 in Pittsburgh. http://www.duq.edu/events/jfk

A while back, Bill Kelly contacted Primeau Forensics and asked Audio Forensic Expert Ed Primeau to assemble and restore the original Air Force One radio transmissions that were recorded the day JFK was assassinated 50 years ago.

According to Primeau, ‘the quality of technology back then was very poor which weighs heavy on understanding the dialogue of the radio transmissions even after restoration’. Then Primeau had an idea, to have Partner Company Primeau Productions create a video which displays the wording on the bottom of the screen displaying the dialogue from the radio transmissions as they occurred.

Primeau sought some authentic footage from a private jet cockpit via a pilot who is a friend of Primeau Productions so the background footage adds an interesting background to the closed caption type text.

For more information on the conference contact:

Deborah G. Jozwiak

320 Fisher Hall
600 Forbes Avenue
Pittsburgh, PA 15282
Email: wechtinstitute@duq.edu
Phone: 412-396-1330
Fax: 412-396-1331

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Digital Audio Enhancement and Authentication/Audio and Sound Restoration

Tuesday, January 1st, 2013

audio restorationDuring the last quarter of 2012 I saw an increasing demand from litigators requesting the audio portion of video recordings, as well as concealed audio recordings, to be enhanced – or, as I prefer to designate it, clarified and authenticated- in order to better hear the series of events that have been recorded digitally.

Since just about every case that I have worked on over the past several years has been recorded on digital media, the process for authentication and clarification using digital forensic software programs is extremely beneficial for litigators.

One of the techniques that I use that I would like to share in this blog post is to create several filters to apply to the audio file which in turn result in several enhanced or clarified ‘revised’ audio files. In other words, I listen to an audio file and create filters to apply to better hear the desired conversation. Each filter applied results in a separate audio file of the recording or version one, two, three and so on.

I go back to the raw ‘original’ file a second, third, fourth … up to ten times, creating different filters each time to apply to the original audio file in order to hear different parts of the conversation that may be masked or covered by different background sounds.

Because I have a ‘trained ear’ and have been working with spoken word recordings for nearly thirty years, as a practicing audio forensic expert I have a critical listening skill. This keen sense of hearing that most people don’t have is very important for understanding poorly recorded conversation.

I use this listening skill and create a forensic transcript. The forensic transcript helps the litigators better understand the conversation or poorly recorded audio. The multiple filters and variations of that audio file allow me to hear the conversation in various sections much better in order to create the forensic transcript.

As an example, if I’m conducting a forensic investigation and trying to determine what is being said in a busy restaurant where there are other voices talking, dishes clanking, and even music playing I will apply filters to the recording and then listen to the recording and write down the words that I can hear from that first filter application.

Then I will go back to the original file and create different filters to help remove different parts of the background noise to allow me to hear additional words that I may not have been able to hear from the first filtering pass. The combination of creating multiple restored files and a forensic transcript has been very successful. I see this forensic application being very successful and necessary in the future.

The need for a forensic expert to enhance, or clarify, audio recordings will increase due to the number of conversations that are being recorded in public places. Forensic processes similar to this will be extremely important as technology changes and more and more clarification becomes necessary.

photo credit: 24/96 via photopin (license)

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The Art and Science of Removing and Restoring Audio From Video

Friday, November 16th, 2012

5570870656_81ed95b87c_oAs an audio forensic expert I often receive video evidence that has an audio track that is difficult to understand. Even though the video presents clues and truth about the events as they occurred in the video the audio track also provides an opportunity of clues and events as they occurred to help process the litigation. As both an audio and video forensic expert I am often asked to clarify or enhance the audio from a video. The process of removing the audio track for enhancement and clarification is crucial to the success of presenting the enhanced or clarified audio evidence in court.

First of all, most people look for audio enhancement when they come to me as an audio forensic expert, and I often start our conversation out by explaining to them it’s better to use the word ‘clarify’, because judges and courts don’t understand the semantics and the difference between the words ‘enhanced’ and ‘clarified’. Clarified has less harmful meaning than enhanced. If I’m in court and I tell a judge that I’ve enhanced this audio one of the first things the judge thinks is that something has been done to it to take it or change it from its original state, and that’s not the case. But, most people are educated and search for audio enhancement when they’re looking for an expert to help solve their problem or clarify their evidence.

Removing the audio track to be processed requires the video forensic process of loading the evidence into a software program like Premiere Pro or Final Cut Pro then exporting the audio track in full quality from that video to create a sub-file, which is an audio only file. That file is then imported into Adobe Audition or Sound Forge depending on the nature of the clarification that is necessary. I find Adobe Audition to have more powerful tools to help the clarification process. I use tools in Audition in order to remove unwanted noise and increase the wanted sounds which could be speech, gun noises and other extraneous noises to the environment which could be crucial to the understanding of the events as they occurred. The tools that I use, that I apply to the audio export file, are used in accordance with accepted standards in the scientific community so that if this case were to go court I could explain, by my work product and my notes, what filters or tools were applied to this digital audio file in order to clarify the sounds to be better heard, or the speech to be better understood. Once I’m satisfied with the clarification process and I believe the file has been enhanced as much as possible the exact file, in it’s restored process – which is more clarified and enhanced – is re-imported to the video software program and reconnected to the original video evidence. At that point it is synched with the audio file that was originally part of that video evidence and exported to create the clarified version of that evidence. If there’s any video work that needs to be a part of that process, such as sharpening of the image, zooming in of the video image, that is also done before exporting the new clarified evidence to be used in the litigation. The processes are accepted in the scientific community and an important part of the forensic expert’s job. Keeping track of the steps along the way – including chain of custody of the evidence – is crucial and part of the audio forensic clarification/restoration process.

photo credit: J·K·L (87/365) via photopin (license)

 

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A Three Part Process for Audio Restoration

Wednesday, July 13th, 2011

audio restorationIn the following blog post, I will help you understand a basic three part process for audio restoration. In the embedded video, I exhibit an audio file that was lifted from a video which is in need of some audio restoration. The video walks you through the process which varied from video to video in this video training set.

The first step is to either compress the audio increasing the gain during the process or removing any unwanted distortion; whichever you feel is best to lead with. You can try one process first then the second. Worse case you can apply the processes in opposite order if your initial results are not up to your expectation.

Varying the order which filters and noise reduction are applied is how a forensic examiner will proceed when restoring an audio file. Audio restoration takes time, patience and good critical listening skills.

The three filters I will demonstrate in this video are wave hammer, equalization and noise reduction. I use Sony Sound Forge software 9.0 for this example. Other audio software programs can be used and more than likely include similar filters to those found in Sound Forge.

 

 photo credit: Mixer Controls: Sliders Faders Buttons Switches Knobs via photopin (license)

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