[Nfbmo] sound editing

Gary Wunder gwunder at earthlink.net
Fri Apr 10 19:59:32 UTC 2009

Pete, your work is most interesting. I am going to post to our list for 
folks who are interested in such things.


----- Original Message ----- 
From: "Peter Donahue" <pdonahue1 at sbcglobal.net>
To: "Gary Wunder" <gwunder at earthlink.net>
Sent: Friday, April 10, 2009 2:22 PM
Subject: sound editing

> Hello Gary,
>    Glad to hear from you this morning. Digital-audio editing and clean-up
> is quite an art. It involves several steps before I post the files to the
> server for the Web site.
>    Since the vast majorrity of PCS out there have a player capable of
> handling MP3 Files the first thing I'll do with the .wma files you sent me
> is to convert them to .mp3 format using Sound Forge. When the files are
> being saved in the new format I'll rename them so they have a filename 
> that
> gives the name of the organization or affiliate followed by the year and 
> the
> particular session; (nfbmo2009_saturday_morning.mp3). Since NFB Net runs
> under UNIX and UNIX is fussy where case sensitivity is concerned I use all
> lower case characters in file and folder names to avoid case wars when
> content is uploaded to the server For example.
>    Next I crop the beginning and end of each file to get rid of the
> chit-chat that goes on before the session begins or after it ends. When
> possible I leave a few seconds to a minute of the conversation on the ends
> and apply a fade in or a fade out depending if I'm working on the 
> beginning
> or the end of a file.
>    Now it's time to manipulate the audio itself. I'll perform three or 
> four
> operations to improve the audio quallity depending on how the file sounds
> when I receive it. These procedures are:
> 1. Removal of DC Offsets.
> 2. Normalization. Normalizing the recording sets all audio captured to a
> single playback level.
> 3. Adjusting the volume. Since I record at a low record volume to prevent
> distortion I often must raise the playback volume up so the audio can be
> heard by most people.
> 4. I use the Sound Forge equalizer to enhance the audio quality by giving 
> it
> a fuller sound by manipulating the trebble, mid range or base. I often 
> find
> that boosting the base does much to give the recording a fuller sound.
> 5. I further enhance the audio quallity in some instances by applying
> dynamic compression. The application of dynamic compression in addition to
> normalization often goes a long way to giving the recording a fuller sound
> and a wider dynamic range making it sound almost as good as if it was made
> from bleeding the P.A. system in the meeting room.
>    Now it's time to separate the men from the boys. Once the audio is
> sounding the way I want it it's time to listen to each recording through 
> to
> spot and edit unwanted audio. This can be such things as long gaps of
> silence, microphone noise, (Something I like to call microphone wars),
> audience noise, conversations such as those you often pick up due to your
> recorder being on the podium or those related to management of the
> convention stream, (Most of the time these can be removed if there isn't a
> mager presentation in progress), and other audio anomalies that are
> distracting to listeners.In Sound Forge you do this by locating the audio
> you wish to remove, set a marker before and after it, and using standard
> Windows Commands such as cut, copy, depending if you want to to remove
> unwanted audio or if you're copying an entire presentation to the clip 
> board
> to be saved in its own file.
> Since much of this noise occurs during door prize drawings I remove door
> prize drawings from the recordings. Doing this also reduces the file size
> and the amount of disk space needed to store the files on the server.
>    After the files are cleaned up it's on to presentation extraction. I'll
> go through each session file and save each major presentation in its own
> file, (nfbmo2009_presidential_report.mp3) for example. Doing this permits
> site visitors to hear a particular presentation in addition to listening 
> to
> the entire convention session from beginning to end. Extracting convention
> presentationsalso permits them to be made available from other areas of 
> the
> Web site. For example the presentations about Mission Believe could be
> included in an area devoted to that activity. These presentations could 
> also
> be sent to individuals willing to produce text transcriptions of them for
> the Web site or other uses by the affiliate.
> One of the hold ups on posting the 2008 Convention Archives is the fact 
> that
> the CCB Presentation wasn't listedin the agenda. I'm needing to listen to
> the saturday afternoon session to see when they spoke in order to add them
> to the agenda along with the link to the audio file of their presentation.
> I also need to extract some presentations from Sunday Morning. Once that 
> is
> done and I add the pictures and other material to that archive it will be
> ready for prime time with 2009 to follow.
>    When the audio is prepared for the Web site it's time to upload
> everything to NFB Net along with the site pages from where it will be
> accessed. I then test every single link to be sure it works correctly 
> before
> bringing the page live on the Web site.
>        Mr. Chairman you now know how Pete Donahue prepares audio for
> posting to our Web sites. Now to figure out how a blind person can do the
> same with digital video. Perhaps the trickiest part of doing digital video
> blind is being able to independently sinc audio with video. For example 
> when
> you hear President Wunder gavveling the convention session to order you 
> must
> be able to see him striking the gavel in the video. If the audio and video
> are not sinced properly you could end up with something like hearing
> President Wunder gavveling the convention to order, but the video would 
> show
> him chatting with a conventioneer in the audience. That's another puzzle 
> for
> us to figure out. Again all the best to you and Debbie for a wonderful
> Easter Weekend.
> Peter Donahue

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