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Digital Audio: Working with MP3 Sound Files using Sound Companion


Audacity and Sound Companion 2 can import and export in the MP3 format. Audacity uses more current MP3 standards so it is the recommended audio editing application for editing/exporting in the MP3 format. There are several benefits when using the MP3 format for your sound files. The most significant one is the much smaller file size that it produces, when compared to standard WAV formatted files. It is important to note that the audio quality remains high even though the file size is much smaller.

As with other types of media (graphics, video, animations,) it is important to know your "targets" before deciding which audio format and "settings" to use for preparing your digital sound files. These "targets" may include: the total length (in real time) of sound clip, the minimum level of hardware* and operating systems you want the file to be able to play back successfully on, the quality of the speaker system that will be used to play back the files, the level of importance that "file size vs. quality" (optimization) will be needed to insure "user-friendly" download times and/or storage capacity of the media (floppy, CD, ZIP, HD, etc.) that the final production (project) will need to fit on.

*Another factor is what type and quality of sound card is being used. To keep this tutorial from becoming overly technical, you will find out easy enough when you begin testing your sound samples as outlined below, if your sound card is going to cooperate or not.

The best way to go about this process is to think about your project/production "backwards". Another words, specifically what computer is going to play these files in the end. Does it have a Windows 98 or higher operating system on it? (or System 7 or higher Mac OS?) If your project is in PowerPoint, is it the version from Office 2000 or later? or is your project in HyperStudio? Is total file size an important target for this particular project? Is stereo playback important or will monaural (mono) be acceptable?

Once these answers are available the next step is to TEST! Make sure to jot down notes as you go, to keep track of which settings/formats you are using for each test file. Create a small sample sound file. But make sure it is at least long enough to determine it's playback quality when testing. If the project you are working on is going to have music, then make sure and use music (as opposed to just voice narration) for the testing. Next prepare the sample clip with a variety of settings and formats. Make sure to include at least one sample in a standard WAV format and one in an MP3 format. When you have finished preparing the samples don't just play them back and leave it at that. Instead, go ahead and create a sample PowerPoint, HyperStudio, Flash, Premiere Elements, etc. project, as needed, and insert your sample sound file into it. Now test and compare playback compatibility, performance, quality, and reliability. If possible, use the same type computer and type of speakers and/or sound system that will be used for final presentation or performance of your work.

If your testing indicates that the MP3 file format is going to produce acceptable sound quality and seems to playback reliably with the hardware and software needed, then USE IT! It will save you tons of bandwidth (file size), which can translate to many potential benefits, including smaller total file size and storage needed for your project/production, faster load times during performance, smoother playback, and decrease in chance for "crashes" or "lockups" during performance!

Here is a walk-through of the process. This example uses a pre-recorded WAV file that will be converted to an MP3 format and then tested in PowerPoint 2000.

1. Launch the "Sound Music Loops" Browser. If you are on a PISD networked workstation these icons are located in the "Multimedia" directory from your district desktop window. Navigate to the sound called "Industrial."
With "Industrial" highlighted, click the Save button on the Music Loops Browser. Save the file to a location on your personal (H:) drive. Preferably in a directory you've created called "Sound Archive" or something similar.

2. Start Audacity or Sound Companion. Choose File < Open. Navigate to the location of your saved "industrial.wav" file from the previous step.

3. Select and open the "industrial" sound file.

4. First, let's check what the current "properties" are for the existing WAV file. Choose Sound > Sound Format. The window should look similar to this:

5. Click OK to close the Sound Format window. In this example we want to change the "Sound Format" in order to save file space and test for sound quality and compatibility with PowerPoint 2000. Do the following.

6. Choose File>Save As. DO NOT PRESS SAVE BUTTON until you do the following:
a) Change the name of this file to "MP3industrial"
b) Check/make sure that it is going to save it in same directory that your regular "industrial" file is. (Should be in Sound Archives or similar directory on your personal (H:) drive.)

c) Click on the drop-down list beside "Save as type:" and select "MP3 audio files (*.mp3)". DON'T PRESS THE SAVE BUTTON YET!

d) Finally, click on the "Options" button located at the bottom of the Save As window. The window will look like this:

Change the format and attributes to match those in the following graphic:

7. Click OK. NOW CLICK the SAVE button! You should see a progress indicator processing/converting your file. It may take several seconds, depending on the speed of the machine you are working on and how long the clip is. When it is done, close out of Sound Companion.

Testing the File

To test (hear) your file, make sure that you have some headphones or speakers set up and plugged into the correct port (spkr out) on your computer's sound card (located at the back of the computer). You also may need to adjust the Windows "Volume" slider, by clicking once on the sound icon in the lower right corner of your desktop and adjusting. (Some headphones/speakers also have their own volume controls to adjust as well).

1. Open Windows Media Player from Multimedia Folder on your district desktop.

2. Choose File > Open and navigate to the location of your test files. (Personal H: drive > sound archives.)

3. Select the original "industrial.wav" file first and listen to it. Press the "Play" button if it doesn't start to play back automatically. Play it once again to get a good feel for it's playback quality etc.

4. Next, return to File>Open and navigate to the converted version. Select the "MP3industrial.mp3" file and listen to it. Play it again as needed. If you are satified with the playback quality comparisons proceed to the next step.

5. Now for coolest part! Drum roll please.................
Return to File>Open (in Windows Media Player) and navigate to the directory where your two test files are, but this time once you can see them both listed in the window, instead of selecting and opening one of them, just click on "View Menu", located in the upper right hand corner of the "Open" window, and select "details" from the list. This will display the "file sizes" so you can see the huge difference between to two sizes and yet little or no audible difference in the quality of the playback!!!

When done observing the file sizes, just click cancel, and then close Windows Media Player.

Testing with an Application

1. Your file is now ready to test in an application. For this test we'll use PowerPoint. To keep things brief for the scope of this tutorial, just create a simple PowerPoint file with one blank slide in it.

2. Choose Insert > Movies and Sounds > Sound from File. "Navigate to" and select your MP3industrial.mp3 file and click OK.

3. You should get the following prompt.

4. For this tutorial and test, just click Yes. (Certainly you could program this to suit your needs in a real project.)

5. Making sure your speakers/headphones are working and ready, choose Slide Show > View Show.

6. Your test is now complete.

Summary on MP3 Format Use

As mentioned earlier, testing is the key! Once you have determined that the MP3 format is going to work effectively for your particular project, then you can continue with investing some time in converting your WAV files into this format.

As with any media preparation and production for use in your classroom multimedia projects, make sure that you follow all copyright and fair use guidelines, as well as any "end-user" agreements and usage rights for any source material you are intending to use. You are required to follow these as stated in the Acceptable Use policies as well. The following site can be helpful with determining some of these basics. The Copyright Site. Your campus Learning Media Specialist(s) (librarians) are another great source to consult as well.

There may be times and/or project needs when you are recording "live" from a microphone or other source, such as, CD. If permissable, you may want to "capture" these files in an MP3 format to begin with, prior to editing. To do so, follow the same instructions in the "Recording "live" audio" or the "Working with music cds" tutorials, but before you begin recording, choose Sound > Sound Format and choose the format and settings you wish to record with. Be advised that some formats may not be compatible with your system. The best method will be to test first, then decide!

Here are some settings that have worked for me in the past, when desiring to record/capture files in the MP3 format initially, using Sound Companion 2: Go to Sound > Sound Format and change the "File Format" drop-down choice at the bottom of the Sound Format window, to "MP3 audio format", then click the button to the right, labeled, "Options" and select "24 kBits/s, 22,050 Hz, Mono," from the drop-down for "Attributes." Click OK to close the Sound Format window and then proceed with your recording session as normal.

This page last modified June 20, 2007

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