Using Audacity: Recording Audio with Audacity


Familiarise yourself with Audacity’s controls

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  1. Under the Record Meter select Monitor Input.
  2. While speaking into the microphone, adjust the microphone level by sliding the Record Volume fader so that the Record Meter on the far right (RED peaks between –12db and 0db.
  3. Once the recording level is set, press the Record button and speak into your microphone to begin recording. Perform a test recording.
  4. Stop the test recording by clicking on the Stop button.
  5. As you start recording, a digital waveform will appear in the edit window.

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The default scale for the amplitude of the waveform (Y axis) is 0-1, where 1 or 100% is the loudest a signal can be prior to distortion or clipping. The height of the waveform is indicated by a scale of 0 to 1.00, which can be thought of as 0 to 100% of maximum digital volume.

In audio circles amplitude is conventionally measured in decibels or db with lower levels measured as negative values right down to no signal at all, silence represented as infinity.

The scale can be optionally set to measure db instead of the default 0-100% scale

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Notice that in the example above the voice peaks in the record meter at around - 6 db. Anything recorded over 0 db (100%) will clip and sound distorted when played back. Aim for your maximum peaks to be around the -5 db point, well within the safety limits and no distortion

Playback


  1. Click on the Rewind Back button.
  2. Click on the Play button, and check the recording.

Playback of the audio can start anywhere simply place the cursor along the waveform. To do this, click the cursor at the required time, and press the play button.

Saving your recording


  1. Click on FILE
  2. Select Export as WAV
    Saving as a wave file has a few advantages: it is easy to edit and update later on; it can be easily used in other audio editing software; and it retains the original quality of the audio recording. By default the wave file will be saved in the Audacity folder but you can save it in any folder you choose.

Editing Audio with Audacity



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This is an example of a 3 minute 30 sec recording. By clicking on the right hand magnifying glass we can view the entire waveform in its entirety.
To play the audio, place the cursor at zero min in the waveform window, and press play. At around the 20-second mark there is a pause in the recording shown by the period of silence.

To edit more accurately, we can highlight the first 20 sec and zoom by placing the cursor in the waveform window and highlighting the waveform to the 20 sec mark on the time scale. Click on the zoom to fit magnifying glass zoom_to_fit.jpg and zoom in on the highlighted section

Now we can see more clearly the pause that starts at 20 secs and ends at about 21 secs. To delete a portion of this pause click the cursor on the end of the sentence, and drag forward to about ¾ way through the pause. Just before waveform begins again.
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Click on the cut button - the one with the scissors icon - to delete the highlighted portion. You can also hit the delete key. There is an undo button if you need to alter the action.

If you wish to view a larger presentation of the waveform, whilst editing, click on View along the top row, a drop down menu appears, scroll down to View Vertically. The waveform will now expand to a larger size, making editing easier.
When editing, do a Save Project As and label as Version 2 edit. If you are happy with each edit, then Save Project as you go along. This way you can always return to the original audio file.

Special Effects and Processing


Audacity comes with a range of special effects and audio processing functions you can apply to your audio files.

Fading-in and Fading-out

Highlight the section of track you wish to fade out
Go to the drop down Effects Menu
Select fade out
Any thing that is highlighted will now be faded out, to no sound at all. This can be useful to transition between audio segments or end a recording gracefully.

Normalising


The Normalising Effect scan the peak amplitude across the selected range and raises the value to 0 db and raises the rest of the file by the same proportion. This way the loudest part of the file is at 0 db. This is fine if the overall levels of the file are consistent and uniform but if thee are spikes often it does not alter the file much as the spikes are already at 0 db. Normalising is found under the effects menu.


Noise Reduction


In the Effects Tools Menu, you will find a very useful tool for reducing unwanted background noise. It's not uncommon to have unwanted environmental noise such as air-conditioning mixed in with your recording.

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This tool works best if you can take a sample of the noise and use it as a profile to apply to and entire section of the recording. The software will then endeavour to subratct or filter out the noise from the file.

To use the noise reduction tool,

Highlight a small section of the unwanted background noise

From the effects menu, select noise reduction

A dialogue box will appear click the noise profile button

Audacity then samples all the Audio Frequencies in the unwanted noise profile. Generally these are very low bass frequencies.

Select and highlight the entire waveform that needs to be filtered. Select preview, and slide the adjustable fader (lees or more) and determine how much noise reduction you wish to apply. Less is always better, too much noise reduction will create strange and unnatural effects on the recording you wish to keep. Once you are happy with your setting, press the remove noise button. The unwanted noise will be eliminated from the selected waveform.

It's a good idea to prepare for this when your recording by recording a representative sample of the environmental noise which you can use as a profile.