class xi · introduction and recording audio what is audacity ? audacity is a free audio recording...

CLASS XI Total Duration

160 minutes

Learning Outcomes

The learning outcomes expected by the end of the academic year are that ,the students will be able

to: 1. Record live audio

2. Edit audio flies

3. Mix sounds

4. Export audio files in formats as MP3, WAV.

Concepts Covered

Recording, Importing files, Editing, Narration, Mixing, Built in effects, Save and Export file.

Content Outline

Introduction and Recording Audio. • What is Audacity?

• Why Audacity?

• Recording Audio

• Import music file

• Track control panel

• Recording more than one audio.

Editing Audio • Editing tools --- Select ,Envelope

• Remove DC offset

• Delete silence

• Reduce Amplification

• Some more built in effects

Recording and Mixing Narration with Music • Record Narration

• Edit Narration

o Leveling out volume`

o Cutting the Narration track

• Marking start of narration in the

background music

• Moving the narration clip to work with

music

• Mix

Saving file • Saving file and Exporting audio

Sources: http://www.manual.audacityteam.org/man/tutorial_editing_an_existing_file.html

AUDACITY

Introduction and Recording Audio

What is Audacity? Audacity is a free audio recording software program

Why Audacity?

Audacity eliminates the need for a stand-alone audio recorder. If you have a computer,

with either a built-in microphone or an attached external microphone, you can download

the free Audacity program and begin your journey into the world of digital audio recording

and editing.

Ways to use Audacity

You can record audio using a built-in or external microphone, or you can import an audio

file to edit. You can also use a patch cable to record directly from another computer or

audio source.

Let’s start recording

This is what your screen will look like when you first open Audacity and haven’t started

recording. To start recording, click on the Record button. To stop recording, click on the

Stop button. For editing practice, record speaking softly, then more loudly. Also, leave a

few seconds of silence at the end of your recording before clicking the stop button.

Your Recorded Audio After you record your audio, you will see that your blank screen has been replaced with

a “Track” containing your audio file, and you can see the audio recording length, and

audio characteristics. You can edit this recorded audio, or you can record more audio.

This is your recording timeline. It shows you the length of your recording in seconds or

minutes/seconds.

This is your Track showing the waveform of your recorded audio, and how the amplitude

changes with the loudness of your recording.

Recorded audio often varies in loudness, but with Audacity, you can edit the recorded

audio to make it louder or less loud. You can

such as recorded silence.

Import the file into Audacity

First launch Audacity, then import an audio file by selecting File > Import >

A quicker method is to just drag and drop the file as in the following examples:


showing the waveform of your recorded audio, and how the amplitude

changes with the loudness of your recording.


audio to make it louder or less loud. You can also delete portions of recorded audio,

First launch Audacity, then import an audio file by selecting File > Import >Audio...

A quicker method is to just drag and drop the file as in the following examples:


showing the waveform of your recorded audio, and how the amplitude


also delete portions of recorded audio,

Audio....

Track Control Panel

Controls

• Close Button:

Clicking this button will close the track, removing it from the project.

• Audio Track Dropdown Menu:

Clicking the track name or using SHIFT + M on the currently focused track

opens the Audio TrackDropdownMenugiving options that affect this track on

created tracks are named "Audio Track". Options in the dropdown menu include changing the

name or sample rate, how the track is displayed, splitting a stereo track to single left, right or

mono tracks and swapping stereo channels.

• Mute Button:

Click to silence this track when playing.

• Solo Button:

Click to play just this track. Click again to release the button.

• Gain Slider:

Set the gain for this track. Hold down the shift key while dragging to adjust the

slider in finer increments. Double

precise adjustments or enter a gain value.

• Pan Slider:

To make signal stronger on left or right earphone. Hold down the shift key

Clicking this button will close the track, removing it from the project.

udio Track Dropdown Menu:


opens the Audio TrackDropdownMenugiving options that affect this track on


how the track is displayed, splitting a stereo track to single left, right or

mono tracks and swapping stereo channels.

Click to silence this track when playing.

Click to play just this track. Click again to release the button.


slider in finer increments. Double-click the slider to bring up a window where you can make

precise adjustments or enter a gain value.



opens the Audio TrackDropdownMenugiving options that affect this track only. Newly


how the track is displayed, splitting a stereo track to single left, right or


click the slider to bring up a window where you can make


while dragging to adjust the slider in finer increments. Double-click the slider to bring up a

window where you can make precise adjustments or enter a pan value.

• Track Collapse Button:

Click on this to make the track 'fold up' into a smaller size. Click again, or drag the

lower edge of the track to restore the size.

Recording more Audio

Sometimes, you will record a segment of audio, stop, and then record more audio. To do

so, click at the end of the waveform. This will allow you to start recording at that point in

the timeline. Audacity treats multiple recorded tracks like transparencies. If you don’t

click at the end of the waveform, you may end up with two tracks on top of each other,

which isn’t good if you’re recording voice.

You now see that I have two recorded tracks, and that the second track starts where the

first track ends.

If you forgot to click the point in the timeline where you want to start recording, you can

move the audio to a new point in the timeline. We do so with the Timeshift tool.Once you’ve

clicked on the Timeshift tool, move your cursor onto the audio you want to move and then click and

drag to the

desired

location in the

timeline.

Audacity’s editing tools

• Select Tool The default editing tool is the Selection tool that looks like an “I” beam. This too

you to click and drag over your waveform to select areas you want to edit.

• Envelope Tool

Used to ajust the volume levels.

Removing any DC offset (if present)

DC offset can occur in audio files so that the recorded waveform is not centered on the horizontal

line at 0.0 amplitude. It can be caused by recording with a faulty soundcard. The example above is

centered on 0 correctly and carries no DC offset.

Accessed by:Effect>Normalize...

The default editing tool is the Selection tool that looks like an “I” beam. This tool allows

you to click and drag over your waveform to select areas you want to edit.

Removing any DC offset (if present)


. It can be caused by recording with a faulty soundcard. The example above is

centered on 0 correctly and carries no DC offset.

l allows


. It can be caused by recording with a faulty soundcard. The example above is

When this box is checked Normalize attempts to remove any DC offset in the selection by centering

the waveform on the 0.0 amplitude level.

DC offset is an offsetting of a signal from zero. On the Audacity waveform it would mean that the

waveform in default view appears not to be centered on the 0.0 horizontal line, as in the upper track

of the above image.

For example, the voltage may be directly caused by a faulty soundcard, or may come from some

other device that is attached to the card

with defective or poor quality hardware it may become large enough to be a problem. DC offset can

cause inaudible low level distortion. The distortion may become audible when effects that chang

the frequency content are applied, or when exporting the audio to a size

MP3.

Delete Silence

Let’s use the Selection tool to select the area of silence at the end of our recording.

After the click and drag, your area of silence will be highlighted. Click the Delete button on your

keyboard to delete the silence.


the waveform on the 0.0 amplitude level.




other device that is attached to the card. Any offset is normally so small as to not be noticeable, but


cause inaudible low level distortion. The distortion may become audible when effects that chang

the frequency content are applied, or when exporting the audio to a size-compressed format like

Selection tool to select the area of silence at the end of our recording.

of silence will be highlighted. Click the Delete button on your





. Any offset is normally so small as to not be noticeable, but


cause inaudible low level distortion. The distortion may become audible when effects that change

compressed format like

Selection tool to select the area of silence at the end of our recording.

of silence will be highlighted. Click the Delete button on your

Reduce Amplification

Sometimes the recorded audio is so loud, it causes distortion to the finished audio. You

can reduce the amplification. As you can see from the waveform below, the amplitude of

a portion of the recorded audio reaches the top and bottom of the track area. This

signifies that the recording was very loud and needs to be reduced.

To reduce the amplification, once again we will use the Selection Tool to click and drag

over the portion of the waveform that we want to edit.

After you’ve highlighted your section of loud audio that you want to reduce, click Effect

and Amplify.

After selecting Amplify, you will see the box above.To reduce amplification click and drag the

slider to the left. The decibel level changes. Click OK to reduce your highlighted audio by the

specified decibel level.

Some Built-in effects Audacity's built-in effects (those that appear in the program irrespective of the contents of your

Audacity and other "Plug-Ins" folders) are above the divider in the Effect menu.

Amplify...

Increases or decreases the volume of the audio you have selected. When you open the dialog,

Audacity automatically calculates the maximum amount you could amplify the selected audio

without causing clipping (distortion caused by trying to make the audio too loud).

Auto Duck...

Reduces (ducks) the volume of one or more tracks whenever the volume of a specified "control"

track reaches a particular level. Typically used to make a music track softer whenever speech in a

commentary track is heard.

Change Pitch...

Change the pitch of a track without changing its tempo.

Change Speed...

Change the speed of a track, also changing its pitch.

Change Tempo...

Change the tempo of a selection without changing its pitch.

Click Removal...

Click Removal is designed to remove clicks on audio tracks and is especially suited to declicking

recordings made from vinyl records. It will usually work best on very short clicks. For broader

individual pops in selections up to 128 samples wide (about three milliseconds at 44100 Hz project

rate).

Compressor...

Compresses the dynamic range by two alternative methods. The default "RMS" method makes the

louder parts softer, but leaves the quieter audio alone. The alternative "peaks" method makes the

entire audio louder, but amplifies the louder parts less than the quieter parts. Make-up gaincan be

applied to either method, making the result as loud as possible without clipping, but not changing

the dynamic range further.

Echo...

Repeats the selected audio again and again, normally softer each time. The delay time between each

repeat is fixed, with no pause in between each repeat. For a more configurable echo effect with a

variable delay time and pitch-changed echoes.

Equalization...

Adjusts the volume levels of particular frequencies.

Fade In

Applies a fade-in to the selected audio, so that the amplitude changes gradually from silence at the

start of the selection to the original amplitude at the end of the selection. The shape of the fade is

linearThe rapidity of the fade-in depends entirely on the length of the selection it is applied to.

Fade Out

Applies a fade-out to the selected audio, so that the amplitudechanges gradually from the original

amplitude at the start of the selection down to silence at the end of the selection. The shape of the

fade is linear. The rapidity of the fade-out depends entirely on the length of the selection it is

applied to.

Leveler...

Leveler is a simple, combined compressor and limiter effect for reducing the dynamic rangeof

audio. It reduces the difference between loud and soft, making the audio easier to hear in noisy

environments or on small loudspeakers. It is best suited to speech recordings but at heavier settings

or used multiple times it can also be used as a simple distortion effect for voices or instruments.

Noise Reduction...

Reduces constant background noise such as fans, tape noise, or hums. It will not work for removing

talking or music in the background.

Normalize...

Use the Normalize effect to set the maximum amplitude of a track, equalize the amplitudes of the

left and right channels of a stereo track and optionally remove any DC Offset from the track.

Narration

Recording and Mixing a Narration With Background Music

The objective is to record a simple narration, add some background music, cut the narration to fit

the music, lower the volume of the music during the narration, and finally mix and export the final

product.

Record the narration

Consider where your microphone is going to be in relation to everything else in the room. Try to

place it so that it picks up a minimum of computer noise (hard drives, fan). When speaking into the

microphone, point the microphone at your mouth but don't point your mouth at the microphone.

Setting up the microphone so that it is level with your mouth but a little off to the side also works.

This avoids "popped p's" and other breath effects from ruining your recording. Finally, try to set up

the microphone so that it is 4 to 6 inches away from your mouth.

While you are talking, try to keep looking in one direction - moving your head left or right, up or

down, while you're talking will change the tonal quality of your voice, and may be distracting to

your listeners. Speak in a normal, conversational tone of voice, but also speak clearly and enunciate

carefully.

NOTE:

If you have just made a recording it is strongly recommended to File > Export Audio.. it

immediately to WAV or AIFF (ideally to an external drive) as a safety copy before you start editing

the project.

Perform a level test of your voice before it is recorded for real. Click on the downward pointing

arrow in the Recording Meter and click "Start Monitoring". While speaking into the microphone as

loudly as you intend, adjust the recording level slider (by the microphone symbol) on the Mixer

Toolbar so the Recording Meter is almost reaching the far right-hand side (but not far enough to

bring the red hold lights on). If the Recording Meter is not visible, click on View > Toolbars and

enable the Meter Toolbar .

Edit the narration

Don't edit too tightly - the final result should sound natural. Use Audacity's Cut Preview feature to

hear how each edit will sound before you make the edit. Then listen back to each edit - undo and try

again if it doesn't sound natural.

Leveling out the volume

Unless you are professional narrator or voice-over specialist there are probably level (volume)

variations during your narration. Remember, your listeners can't see you, so having a consistent

volume for your narration is important so they'll be able to hear and understand everything you're

saying.

You could go through and manually adjust the volume throughout your narration track using the

Envelope Tool, but there's an easier way - use Audacity's built-in Compressor effect. Click on the

Track Control Panel of your narration track to select the entire track then choose Effect

>Compressor.

The Compressor effect works by making the loud parts quieter, then amplifying everything, which

ends up making the quiet parts louder.

• Check Make-up gain for 0dB after compressing and Compress based on Peaks.

• The former means that Compressor will maximize the volume of the track after it

does its work. The latter means that Compressor will look at the peaks of the

waveformrather than its average value.

• The "Threshold" control is the "tipping point" - the point where Compressor decides if

something is "loud" (and should be made quieter) or "quiet" (in which case it leaves it

alone).

• The "Noise Floor" control tells Compressor that anything below that level is noise and it

shouldn't make it any louder.

• The "Ratio" control tells Compressor how much quieter it should make the loud parts.

• Set the "Attack Time" to "0.5 secs"

• Set the "Release Time" to "1.0 secs".

• These two controls tell Compressor how fast it should respond to changes in volume.

Note that once you've gone through setting everything up the first time, on subsequent tries you just

change the Threshold. This make it easy to home in on the setting that works.

Import the background music file

Choose File > Import > Audio and open the background music file you've chosen for the project.

Audacity imports the music file into your project and puts it in its own stereo track.

Look at the Track Control Panel at the left of each track. Note the "Mute" and "Solo" buttons. You

can use these to control which tracks you hear when you click the Play button. Clicking the "Mute"

button will turn that track off . Clicking the "Solo" button will cause only that track to be heard

when you press the Play button.

Cutting the Narration Track (Time-shift the tracks )

Start by clicking the "Solo" button on the narration track - we don't want to listen to the music track

while we're doing this work on the narration track.

Assume that we want to cut the narration into three separate segments. Each of these segments will

begin when the music makes a dramatic change.

Find the spot between the first and second portions of the narration. Using the Selection Tool click

at this point. Choose Edit > Clip Boundaries > Split - a split line appears. There are now two clips

on the narration track. Similarly, put a split point between the second and third portions of the

narration. The narration track will now look something like this:

Marking the places in the background music track where you want the narration clips to start

Remember, our goal is to cut the narration to fit the music. So our next step is to pick the spots in

the background music track where we want the three narration clips to start

Click the "Solo" button on the narration track to turn off the Solo function on that track. Click the

"Solo" button on the background music track so you will only hear that track.

Identify the point in the background music track where you want the narration to begin. Click at that

point with the Selection Tool. Choose Tracks > Add Label at Selection. Type a name for the label,

for example "First Narration".

Similarly, identify the points in the background music track where you want the second and third

narration clips to begin, and create labels at those points.

Moving the clips to work with the music

Click the Solo button on the background music track to turn off the Solo function on that track, so

we can hear both the narration and music tracks.

Using the Time Shift Tool drag the third narration clip so that the start of the clip lines up with

the third label. Audacity will help you line this up perfectly

the third label a yellow BoundarySnapGuidewill light up. Similarly, drag the

to line up with the second label, and drag the first narration clip to line up with the first label.

" button on the narration track to turn off the Solo function on that track. Click the

" button on the background music track so you will only hear that track.


. Choose Tracks > Add Label at Selection. Type a name for the label,

points in the background music track where you want the second and third

narration clips to begin, and create labels at those points.

Moving the clips to work with the music


we can hear both the narration and music tracks.

drag the third narration clip so that the start of the clip lines up with

third label. Audacity will help you line this up perfectly - when the start of the clip lines up with

SnapGuidewill light up. Similarly, drag the second narration clip


" button on the narration track to turn off the Solo function on that track. Click the


. Choose Tracks > Add Label at Selection. Type a name for the label,

points in the background music track where you want the second and third


drag the third narration clip so that the start of the clip lines up with

when the start of the clip lines up with

second narration clip


Adjust relative volume levels

There are at least two ways to do this: manually with the Envelope Tool, or automatically with the

Auto Duck effect.

Using the Envelope Tool

Select the Envelope Tool from the Tools Toolbar. In the music track, click to create a control

point a second or so before the first narration clip begins. Click to create a second control point just

as the narration starts. Drag the second control point down to reduce the volume of the music track.

Click in the Timelinea few seconds before the start of the first narration clip to hear the effect. Press

SPACE to stop playback. Adjust the first and second control p

the fade you want. In a similar manner create the fade up at the end of the first narration clip.

Adjust relative volume levels


from the Tools Toolbar. In the music track, click to create a control


tion starts. Drag the second control point down to reduce the volume of the music track.


SPACE to stop playback. Adjust the first and second control points to get the length and depth of



from the Tools Toolbar. In the music track, click to create a control


tion starts. Drag the second control point down to reduce the volume of the music track.


oints to get the length and depth of


You could continue in this manner doing the fades on the music track for each clip in the narration

track. Or you could try using the Auto Duck effect. The advantage of using the Envelope tool is that

you can always go back and change the fades. Auto Duck, being an effect, permanently alters the

music track.

Smooth fade of the background music

click at the point where you want the music to begin fading out. Again choose Edit > Select >

Cursor to Track End, then Choose Effect > Fade out.

Check your mix

If you maximized the volume of your narration track there is a good chance that when you mix it

with the music track the resulting mix will be too loud and cause clipping - this is a bad thing.

Remember, we maximized the volume and leveled out the loud and soft passages so that people

would be able to hear you. To check for clipping, play back a short portion of the project where

there is narration and background music. Watch the Playback Meter - if clipping occurs the red

"clip bars" will appear at the right-hand end of the Playback Meter. If this happens, use the Track

GainSlider to turn down the volume of both the narration and music tracks to -2 dB. Listen to the

short section again and look for the red clip bars on the Playback Meter. If clipping still occurs, turn

down the volume of the narration and music tracks to -4 dB each.

Optional - Mix and Render

You may want to Mix and Render your project before you export it. The Mix and Render command

(in the Tracks menu) will mix your project, and put the resulting mix in a new track (this is the

"render" portion of the command). This gives you the opportunity to maximize the volume of the

final mix, and do a final check for clipping. If you would like to try this, follow these steps:

• Choose Edit > Select >All

• Mix and Render only mixes the selected tracks - you want to mix all of them

• Choose Tracks >Mix and Render

• your project is mixed into a new stereo track and the previous, separate tracks are

deleted .

Saving an Audacity Project

There are two main commands for saving projects:

• File >Save Project saves a standard project as an AUP project file (a file with ".aup" after its

name) and a _data folder containing the actual audio. .

• File >Save Project As... similarly saves a standard project as an AUP file and _data folder. It

is for saving an empty project or to save an existing Project to a new name to make a copy

of the project in its current state then continue working on that copy.

Saving a project lets you save unfinished work and re-open it later in Audacity exactly as it was,

with all edits and recorded/imported tracks preserved.

Exporting audio files

To make an audio file for playing on your music player, burning CDs or for use in other programs

you must use one of the Export audio commands as Audacity projects can only be opened and used

by Audacity; neither the .aup project file or the .au files in the _data folder can be used in other

programs or devices.

Use File >Export Audio... which brings you to the Export Audio dialog where you can select from

various standard audio file formats according to your purpose.

The two most common formats which can be played almost anywhere are:

• WAV: a lossless very high quality, but large, format ideal for burning to Audio CDs. WAV

files will open, play and can be edited on Windows, Mac OS/X and Linux computers.

• MP3: a lossy lesser quality format but small enough to send over the Internet or store on

portable devices. Typically an MP3 file can be around ten time smaller than the equivalent

WAV. They will also open and play on Windows, Mac OS/X and Linux computers. MP3s

are good for listening and sending or website posting but are poor for editing and

production.

class xi · introduction and recording audio what is audacity ? audacity is a free audio recording...

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