Creating an Audio Lesson
Use Audio Lessons to Enhance Teaching and Learning in Your Classroom
Many of our students are wired for sound already with their cell phones, iPods, and mp3 players. They find audio lessons
to be engaging and interesting. Imagine setting a homework assignment that involved students commenting on
information they listened to using their mp3 players. It is easier to create an audio lesson than you might think.
Planning Your Audio Lesson
The first step to successfully create an audio lesson is to plan your project. Before you begin, identify your intended
audience. Where will they experience your lesson and how? What is the topic of your lesson and what information do
you want to convey to the students in your project? How will you share your audio lesson with your class? Once you
have answered these questions, you can put together your plan.
First, Write It Down!
The most important thing in the creation of your audio lesson is the script. It is easier to polish your presentation before
you record your narration. Jot down what you want to say to avoid those awkward pauses and it will keep you from
stumbling over your words while recording. A script will ensure that you will never forget to include important facts and
information. Be sure to identify any resources you may need in your lesson such as any necessary sound effects.
Equipment
Inspect your equipment to be sure it can produce your lesson. Most computers can produce a remarkably high quality
sound file. You will need to have speakers and a microphone, of course. An optional headset would be even better for
recording your lesson.
The software you will use is very important. It should be easy to use yet full featured. Audacity™ is a free, open source,
cross-platform audio editor. It is available for Windows, Macintosh, and Linux based computers. It can be downloaded
over the Internet from http://audacity.sourceforge.net/.
Toolbars
Control Toolbar
Editing Tools
Selection tool - for selecting the range of audio you want to edit or listen to.
Envelope tool - for changing the volume over time.
Draw tool - for modifying individual samples.
Zoom tool - for zooming in and out.
Timeshift tool - for sliding tracks left or right.
Multi tool - lets you access all of these tools at once depending on the location of the mouse and
the keys you are holding down.
Audio Control Buttons
Skip to Start - moves the cursor to time 0. If you press Play at this point, your project will play
from the beginning.
Play - starts playing audio at the cursor position. If some audio is selected, only the selection is
played.
Loop - if you hold down the Shift key, the Play button changes to a Loop button, which lets
you keep playing the selection over and over again.
Record - starts recording audio at the project sample rate (the sample rate in the lower-left
corner of the window). The new track will begin at the current cursor position, so click the
"Skip to Start" button first if you want the track to begin at time 0.
Pause - temporarily stops playback or recording until you press pause again.
Stop - stops recording or playing. You must do this before applying effects, saving or
exporting.
Skip to End - moves the cursor to the end of the last track.
Mixer Toolbar
The Mixer Toolbar has three controls, used to set the volume levels of your audio device and choose the
input source. The leftmost slider controls the playback volume, the other slider controls the recording
volume, and the control on the right lets you choose the input source (such as "Microphone", "Line In",
"Audio CD", etc.). Use the Record Level Meter to set the correct level.
Changing these controls has no effect on the audio data in your project - in other words it doesn't matter
what the output volume level is when you Export or Save a project - the end result is the same.
Edit Toolbar
All of the buttons on this toolbar perform actions - and with a couple of exceptions, they're all just
shortcuts of existing menu items to save you time.
Holding the mouse over a tool will show a "tooltip" in case you forget which one is which.
Cut
Copy
Paste
Trim away the audio outside the selection
Silence the selected audio
Undo
Redo (repeat last command).
Zoom In
Zoom Out
Fit selection in window - zooms until the selection just fits inside the window.
Fit project in window - zooms until all of the audio just fits inside the window.
Meter Toolbar
The Meter Toolbar is used for monitoring the input and output audio levels. Typically it is used to make
sure that the loudest volume is as loud as possible (for maximum fidelity) without clipping or distorting
it. The output (playback) meter is the green one, on the left in the picture above, and the input
(recording) meter is in red, on the right.
The meters provide a visual indication of the current audio levels going in and out of audacity.
If you float the Meter Toolbar, either by dragging it out of the toolbar or by selecting "Float Meter
Toolbar" from the View menu, you can resize it and even orient it vertically.
Normally the meters are only active when you are playing or recording audio. However, you can also
monitor input when you're not recording - to do this, either select "Monitor Input" from the input meter's
pop-up menu, or else just click on the input meter. If you have a microphone or other input source
attached, you will be able to watch the level of the audio before you start recording.
Each meter shows several characteristics of the audio level at once:
z
z
z
z
z
The right hand end of the meter corresponds to the point at which the audio will be clipped, and
the left hand end is silence
For stereo, the top bar shows the left channel, and the bottom bar shows the right channel.
The brightest part of the bar shows the average audio level (related to the loudness) and the darker
part of the bar shows the peak audio level.
The peak-hold line to the right of this shows the maximum audio level achieved in the last 3
seconds.
Finally, the clipping indicators on the far right of each meter will light up if clipping is detected
(meaning that the audio was too loud and will sound distorted).
If clipping is detected when you are recording, you should stop, lower the volume of your input source,
and start recording again from the start. If the output meter clips then you need to make some or all of
your tracks quieter using the track gain control.
If the level of the input (recording) source is too high, you can try to lower the input level using the
Mixer Toolbar, but if this doesn't work, you should try to lower the volume of the external input source
(e.g., your microphone, cassette player, or record player).
It is possible, especially if you have an older, slower computer, that the Meter Toolbar may interfere
with Audacity's ability to record or play audio with the highest quality, because your computer is so
busy redrawing the meters that it doesn't have time to process enough audio. In this is the case for you,
you can disable the Meter Toolbar in the Interface tab of the Preferences dialog.
Activity
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Purpose
An audio lesson describing the “Water Cycle” will be created. The audio lesson will be used for review by sixth
grade science students. The file will be posted on the classroom web page where it can be accessed at school
and at home.
§112.22. Science, Grade 6 Implementation of Texas Essential Knowledge and Skills for Science, Grade 6
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06SC08
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06SC14
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Scientific Concepts: The student knows that complex interactions occur between matter and energy
B) explain and illustrate the interactions between matter and energy in the water cycle and in the decay of biomass such as in a
compost bin
Scientific Concepts: The student knows the structures and functions of Earth systems
B) identify relationships between groundwater and surface water in a watershed
Script
The earth has a limited amount of water.
That water keeps going around and around and
around and around and (well, you get the idea) in
what we call the "Water Cycle".
This cycle is made up of a few main parts:
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evaporation (and transpiration)
condensation
precipitation
collection
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Resources
Computer with speakers and microphone
Audacity (audio editing program)
Headset (optional)
Sound files for background and sound effects
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Preparation
1. Create a folder named Water Cycle Audio Lesson to contain all files that will be used to create the
project and to serve as the location where the audio lesson will be saved.
2. Copy all resource files to the project folder.
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Instructions
1. Start Audacity™. In the menu bar under “File”, select “Save Project As…”. Name the project “Water
Cycle” and save it in the Water Cycle Audio Lesson folder.
2. In the menu bar under “File”, select “Import” > “Audio…”. Select the file named “Indian Lullaby.mp3”
located in the Water Cycle Audio Lesson folder. This will be the background music for the audio lesson.
3. Click the “Play” button in the control toolbar to review the background music track. (Notice that it is too
loud for a background music track.)
4. In the menu bar, click on “Effect” and select “Amplify”. Set the “Amplification (dB)” to -20.
5. Click the “Play” button in the control toolbar to again review the background music track to ensure it is
now set to an acceptable volume level. Make any desired final adjustments to the volume level.
6. Mute the “Indian Lullaby” track by clicking the “Mute” button.
7. In the mixer toolbar, start monitoring the microphone volume by selecting “Start Monitoring” in the
dropdown menu located beneath the microphone slider control in the mixer toolbar. Read the script in
a clear, normal voice to check the microphone’s volume level. Make all appropriate adjustments to the
microphone’s volume level.
8. With your script in hand and ready to read, click the “Record” button in the toolbar. Read the first
sentence of the script. Press the spacebar when finished to stop recording. Press the spacebar again to
listen to the recording. If you would like to re-record the narration, first delete the track before rerecording the narration.
9. When satisfied with the recording of the first sentence, take the script and prepare to read the second
sentence by muting the previous track. When ready, click the “Record” button in the toolbar and read
the second sentence. Note that a new track has been added to the project. Press the spacebar when
finished to stop recording. Press the spacebar again to review the recording. If you would like to rerecord the narration, first delete the track before re-recording the script.
10. Create another new sound track with the final sentence of the script using these same procedures.
11. Move all recorded narration tracks to one sound track by selecting the wave form, cutting the recording
using the “Cut” command found in the menu bar under “Edit”, and pasting it into the first narration
sound track. Rename the “Audio Track” as “Narration”. Delete each empty track from the project.
12. Click on the “Selection” editing tool located in the control toolbar. Then double-click the last wave form
in the “Narration” track to select it. Use the “Time Shift” editing tool located in the control toolbar to
position the wave form along the “Narration” track. Use this technique to position the other two wave
forms.
13. Unmute the “Indian Lullaby” track and select the track using the “Selection” editing tool. Press the
spacebar to listen to your project. Notice that the background music is too loud during the narrated
passages. To remedy this, apply auto-ducking to the “Indian Lullaby” sound track.
14. First, select the “Indian Lullaby” track using the “Selection” editing tool. Ensure that the narration
passages are positioned in the desired positions along the timeline. In the menu bar under “Effect”,
select “Auto Duck…”. In the dialog box that appears, click and drag the center section of the line
downward until it reads -20. Set the “Threshold” to -50dB. Then click the “OK” button. Notice the
changes to the background music track. Play your project and make any desired adjustments.
15. Add sound effects to your project by importing the file named “thunder.wav” in your Water Cycle Audio
Lesson folder. Rename the sound effects track as “Thunder”. Copy and paste the wave form a few
times along the “Effects” track. Test the volume level of the sound effect in the project and make any
desired adjustments using the “Amplify” effect.
16. Trim your project using the “Cut” or the “Trim” tools.
17. Experiment with the “Fade In” and “Fade Out” effect tools.
18. Save your project.
19. Export your audio lesson by selecting “Export…” under “File” in the menu bar.