Present It! Audio

Editing Audio

To begin a new Audacity project, open the program and then click File > Preferences. Under the Audio I/O tab, select the recording device you would like to use. Under the Quality tab, select the sample rate you want to make your recording in. Whenever possible, choose 44100 Hz. Click OK.

To make a new recording, simply click the red Record button at the top of the application window. As you speak into the microphone, a visual representation of the sound as a waveform will appear in the work area of the application. Click the yellow Stop button to end the recording. Now you're ready to edit your file.

When you’re editing an interview, you should listen for and try to minimize:

Background noise and line noise.
Audible and annoying breathing.
Intrusions like phones, doors closing or dishes clattering.
Mistakes by the speaker, stuttering.
Noises made by the speaker moving.

Click the green Play button to play your recording. As it plays, the cursor will move along the waveform. When you hear something you want to remove — a word, a sound, a breath — use the cursor to highlight the portion of the waveform that represents the sound. Click and hold at the beginning of the sound and drag to highlight a section. Make sure you aren't cutting off any surrounding words. You can cut, copy, paste or delete your selection.

It's quite easy to add a fade to the beginning or end of the file, smoothing out the transition from silence to the background noise of the interview. At the beginning of the waveform, highlight the first few seconds, and choose Effect > Fade In. Repeat at the end of the waveform, choosing Fade Out. You can use the magnifying glass to zoom in on the waveform so that you can more easily isolate the bit you want to fade in or out.

It’s usually a good idea to add a second or so of pure silence to the beginning and end of the file. Place the cursor at the beginning or end of the waveform and choose Generate > Silence. Audacity will insert 30 seconds of silence, which you can trim to the desired length.

Make sure to save often. Keep listening to the sound to make sure you aren’t messing it up. There is no real tried-and-true solution for audio — your ear is the best judge.

If you're worried about making mistakes, save a backup of the original file so that you can revert to it if needed. It is often a good idea to save a couple of copies of your file. One should be the original digitized file, untouched in case you destroy the sound in later versions. You might also save a version of your edit. You can throw away these versions later, but they’ll save you time if you mess up your file and need to go back and try again. If you used a DAT (short for digital audio tape) recorder to make your recording, be sure to label and save your tapes as backup.

Here are a few things you can do to improve interviews while editing:

Replace unwanted sounds like paper shuffling or phones ringing with some of the silence you recorded before you did your interview.
Use background noise to eliminate repeated words, ums, uhs, and other distracting verbal tics. Many times you can also eliminate stuttering.
Add a few beats of background noise between words or sentences to increase intelligibility.
When moving from a voiceover to an interview portion of your audio, use fades (bring the volume gradually down to zero) and cross fades (bring the volume of one audio segment down, while simultaneously bringing the volume of another track up to replace it) to improve the transitional moments.
For recordings with constant background noise like air conditioning or other mechanical hums, try using the Noise Removaleffect.
For recordings with large volume shifts between speakers or over time, use the Normalize effect to boost volumes to the same level where possible.

Once you have finished editing your audio, you should export it as an MP3 file to put on the Web or run it through a streaming encoder. This is the point at which you should compress the audio down to a lower bitrate in order to end up with a smaller file size.

Choose File > Preferences and click on the File Formats tab. If you are exporting as an MP3, look for the MP3 Export Setup and select the appropriate bit rate. Click OK. From the File menu, choose Export as MP3. If you are exporting your audio as a WAV file for streaming, look for the Uncompressed Export Format pull-down menu and choose the quality you would like to export at. From the File menu, choose Export as WAV. You may want to try several versions, beginning with the highest quality, and compare the resulting files.

IMPORTANT: To export audio as an MP3 file you will need to install the LAME MP3 encoder, available on the Audacity Web site.

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