Edit audio quality in Audacity

 


Introduction


This article will guide you through some of the options for editing audio quality in Audacity. This article will teach you 6 basic audio editing functions:

  1. deleting segments

  2. generating silence

  3. noise reduction

  4. normalization

  5. compression

  6. changing track speed

There are more functions available in Audacity that can be used to solve unique audio issues. If you would like assistance with further functions of Audacity or solving audio issues, please contact support@fpcc.ca.

The following videos give audiovisual tutorials for all 6 of the editing steps listed in the remainder of this article. If you prefer written instructions, please scroll past the videos to find the editing instructions you are looking for.


Video Tutorials


 


Deleting Segments (Optional)


Deleting segments in useful for removing interruptions, mistakes, or miscellaneous noises like throat clearing. This is most useful when editing phrases or stories.

If you will be adding labels to your track for exporting, you should do so after deleting segments. Deleting segments will adjust the placement of your labels, which you can adjust, if necessary. If you have already added labels when deleting segments, make sure to drag your cursor into the labels track when selecting your segment for deletion. This will ensure that the time stamp of your label is adjusted when you delete the segment.

 

  1. Listen to your track and visually identify the segment that you want to delete.

  2. Click to the left of the segment, drag your cursor to the right of the segment, and release. This will highlight the segment.

     

  3. Press the "Backspace" button on your keyboard. This will delete the segment.

 


Generating Silence (Optional)


Generating silence is useful if you need to control the 'pacing' of your recording. This is sometimes necessary for stories or for word recordings that use repetition.

If you will be adding labels to your track for exporting, you should do so after generating silence. Generating silence will adjust the placement of your labels, which you can adjust, if necessary.

 

  1. Listen to your track and visually identify the place where you want your segment of silence to begin.

  2. In the Audacity window, go to the "Generate" menu. Find "Silence..." in the list, and click.

     

  3. In the "Silence" window, enter the number of seconds, minutes, or hours of silence that you wish to generate. In this example, 0.5 seconds will be generated:

     

  4. Your silence will appear as a highlighted segment with a flat waveform:

 


Noise Reduction (Optional)


Noise reduction is used to eliminate consistent 'background' noise. This works best for noises from appliances, wind, or other 'ambient' type noises. Noise reduction does not work well for 'interruptions' or noises that are similar in frequency to human speech. People talking, children playing, or dogs barking cannot be eliminated with noise reduction without distorting the speech on your recording.

 


Normalization (Recommended)


Normalization is used to amplify (make louder) sounds that are too quiet, or reduce (make quieter) sounds that are too loud. If your track is consistently too loud or too soft, (above -12db or below -6db), then it is recommended to apply normalization to your whole track. These examples show normalizing individual segments of a track.

  1. Listen to your track and visually identify the segment that you want to amplify or reduce.

  2. Click to the left of the segment, drag your cursor to the right of the segment, and release. This will highlight the segment.

     

  3. In the Audacity window, go to the "Effect" menu. Find "Normalize..." in the list, and click.

     

  4. Normalize your segment to -12db.

     

    1. Segments that are too loud will appear smaller:

       

    2. Segments that are too quiet will appear larger:

 


Compression (Recommended)


Compression should always be the last thing that you do before exporting. Compression smooths the waveform slightly, resulting in a 'cleaner' sound.

  1. Select your whole track by using the "Select" button on the track menu, hitting Ctrl+A on PC, or Command+A on Mac. This will highlight your whole track, giving it a white or light blue colour.

     

  2. In the Compressor window, un-check the box marked "Make up gain for 0 db after compressing". Click "OK".

     

  3. You may notice minor changes to your waveform, resulting in a 'smoothing' effect.

 


Changing Track Speed (Optional)


  1. Select your whole track by using the "Select" button on the track menu, hitting Ctrl+A on PC, or Command+A on Mac. This will highlight your whole track, giving it a white or light blue colour.

     

  2. In the Audacity Window, go to the “Effect” menu, find “Change Speed…” in the list, and click.

     

  3. In the “Percent Change” box, to increase speed, enter a positive number (more than zero). To decrease speed, enter a negative number (less than zero).