For most of the summer, DigiKnow has been looking at preparing teaching content for September and this has touched on how to:
- Record asynchronous content
- Recording online materials (PowerPoint)
- Mediasite
- Deliver synchronous teaching
- Setting up OneNote
- Use discussion forums
- Use of quizzes
In this weeks’ blog post, we look at how to improve recorded audio using Audacity. This blog post will demonstrate some basic editing techniques.
There are other audio editing applications available such as: Filmora, Audio Cutter, Ocenaudio, WavePad, GarageBand, etc. There are YouTube tutorials available for these online and many of these editors are for Windows and MAC.
Before we consider the editing of audio, why do you want to record and where do you want to use the audio?
Why record?
As a teacher, recording yourself and voicing instructions, feedback, etc., can help motivate students to study. It’s quicker to voice short soundbites and these can be uploaded or interspersed throughout a programme of teaching.
You may well be inspiring your students!
Perhaps you have decided to create a weekly podcast or you have set a task for the students to create a weekly podcast together. This firstly gets students planning the structure of the content. Secondly it gets students using other digital skills, i.e., recording and editing with purpose.
Students think about the structure of the podcast. Beginning, middle and end. What do they want to achieve? And, whether the students know it or not, they are collaborating, learning and having fun whilst doing so!
Where can audio be used?
In teaching terms, audio can uploaded to Mediasite or MS Stream (within Queen’s University) and embedded into Canvas as sound bites for your students. Audio can also be embedded onto web pages or virtual walls (i.e., Padlet)
Alternatively, audio can be added on to individual slides in PowerPoint presentations and automated for the slideshow. Audio can also be added to OneNote and other applications.
If you create a weekly podcast of 5 – 10 minutes in length, this can take time to edit but the more you use Audacity, the quicker you will become.
Where the audio is to be used should be decided before you start recording. This can help you determine the length of the audio required and its uses.
Audacity Software
What is Audacity? Audacity is a free and open source audio software that is available free of charge. It works cross-platform for Windows 10, MAC and Linux (and others). It can be downloaded from here.
Audacity has been boasted as an easy-to-use multi-track editor and recorder of audio. Audacity also converts audio files from one type to another, however you decide to export the files.
Libraries
Along with the software, the LAME and FFmpeg import/export Libraries are also required. Why?
LAME MP3 encoder allows audio files to be exported to MP3.
The FFmpeg import/export allows importing and exporting of many audio files from any audio source AND from video files. More info.
MP3 is the audio universal format.
Audacity Overview
- Menu bar
- Transport toolbar (play and record controls)
- Mixer toolbar (mic input / speaker output)
- Edit tool bar (cut, copy, paste, trim audio, blank audio, undo, redo, zoom in, zoom out, etc.)
- Track control panel and audio track (currently a mono track)
- Tools Toolbar
- Play-at-speed toolbar
- Recording/Playback meter tool bar
This is a general overview for BASIC editing. Some of these tools may never be used.
Before we tell you too much, have a look at this video to help orientate you around Audacity’s interface.
Recording in Audacity
You can record straight into Audacity. This allows you to check your audio levels as you go (recording metering bar). The resulting recorded audio can then be edited to improve the audio and bits of audio can be cut out or moved around.
We’ll do this by recording some audio in Audacity.
Make the audio better
When you are recording audio, try to do the following:
- Record in a quiet space
- Turn off system sounds and devices
- Speak clearly and into the microphone
- Check the audio input levels are in the green
- Refer to notes or bullet points
- Be yourself
Improving audio quality (editing)
To improve audio, let’s look at 5 helpful features:
- Amplify levels
- Normalise
- Noise Reduction
- Cut
- Fade In/Out
There are many options but if you’re only starting out, stick with the basics.
Audio production in itself is a science. Personally, I don’t mind a few artifacts in the audio as long as it can be heard, it sounds reasonably good AND it contains the message I want to convey to my audience.
In this scenario, let’s stick with the basic editing of a one audio track.
Amplify
When audio is recorded, it might sound a little lower in volume. This can be boosted with Amplify. It’s a bit like raising the volume.
Normalise
This sets the peak amplitude of the track and balances out any stereo differences (left/right channel).
Noise reduction
Sometimes, there is a little crackle in the audio or a low buzz / hum. If this noise is recorded for several seconds without speech, it can be selected and sampled to check the rest of the audio for the same sound and reduce it. This is noise reduction.
For noise reduction to work, when recording audio, always record a few seconds of ‘silence’ and atmospheric noise. This will help you sample the low level noises you’re not aware of when recording, the static, etc., and help reduce it within your audio file.
Cutting audio and Fade Out / In
Sometimes you might want to remove a section of audio as may not be relevant. Or you made a mistake and did a second recording.
To cut audio, make a selection and click the Scissors icon (pale area on diagram below). This removes (cuts) audio. Then remember to use the Fade Out / In for the audio before and after (indicated with the red highlights below). It’s doesn’t need to be big fades, in fact, smaller selections the fades are applied to is better as it keeps the audio levels up rather than patchy.
The Fade In / Out feature in Audacity is good to use after cutting audio. If you fade out to the cut and fade in from the cut, this sounds better in the audio. Without using Fade In/Out, sometimes the resulting cut audio can sound harsh.
Save as audacity file and Export to MP3
The Audacity project file with be an .AUP file. This can only be viewed or read in Audacity.
To make it MP3 format, go to File and Export, choose Export as MP3.
Save this to a relevant location and add in any metadata tags.
For example, your name as the Artist Name, the name of the track and the year it was created.
Summary
This week, we looked at where audio files could be used and suggested these could be podcasts or soundbites that appear online or in software/applications.
We then looked at some basic editing techniques that could be used to improve recorded audio. This was done in Audacity.
Next week
Next week, Digiknow will be looking at a Teachers’ Toolkit to increase engagement. This will have three blogs per week (Mon/Wed/Fri) for three weeks. This it to help you build up a toolkit of ideas to increase online engagement when teaching.
Needless to say, there will be asynchronous content also. The toolkit still applies!
Please do join us next week to learn more and don’t forget to follow us on Twitter: @MDBSelearn.
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