Digital & Interactive Media · Digital Audio Sound: Sound is simply waves of compressed air that move out from its source, similar to dropping a stone in water. Your ears are sensitive

© UNT in partnership with TEA 1

Digital & Interactive Media

Digital Audio Editing

Digital Audio

Sound:

Sound is simply waves of compressed air that

move out from its source, similar to dropping

a stone in water.

Your ears are sensitive to these compressed

waves. As the sound waves interact with your

ear drum, the signal is sent to your brain,

converting them to the sounds that you

recognize.

© UNT in partnership with TEA 2IT: Digital and Interactive Media – Digital Audio Editing

Digital Audio

Analog Sound

© UNT in partnership with TEA IT: Digital and Interactive Media – Digital Audio Editing 3

Analog sound is recorded by using some property of the

original sound to reproduce the signal.

Often when analog sound is recorded, external

interference, called noise, can get recorded each time

the sound is re-recorded, resulting in each generation of

the recording losing quality.

Digital Audio


Digital Sound

Digital audio is sound that has been stored as numerical

data which can be easily reproduced and manipulated.

Digital sound can be reproduced numerous times without

losing quality.

Audio Equipment

In addition to your computer, the only

additional piece of hardware you will need is

a microphone.

A simple PC microphone will work.


Make sure the microphone is

connected to the microphone

input on your computer.

Audio Equipment

You will also need some recording and

editing software as well. For this lesson we

will use an audio editing program called

Audacity.

Audacity is an Open Source Audio Editing

application that can be downloaded and

distributed for free.


Basics of Audacity

Open Audacity

Should have an icon that looks like

blue ear phones with sound waves.


Basics of Audacity


●Record

●Skip to End

●Skip to Start

●Stop

●Playback

●Pause

Basics of Audacity

Mixer Toolbar


•The left slider is the volume control of the playback.

•The right slider is the Recoding Volume

•Dropdown menu allows you to select the input source for recording.

Basics of Audacity

Editing Toolbar


Cut

Copy

Paste

Trip Outside Selection

Silence Selection

Undo

Redo

Zoom In

Zoom Out

Fit selection in Window

Fit project in Window

The Editing Toolbar

provides many

shortcuts to

common editing

tools used to modify

audio clips.

Basics of Audacity

Audacity Project File

.aup

Can be reopened and individual components can

be edited.

Cannot be read on standard audio players.

Common Audio file types

.wav – Windows audio file

.mp3 – Requires an additional update to create


Using Audacity

We will first create a simple recorded audio

clip using your own voice .

You will need to make sure your microphone

is properly connected to your computer.

Next, make sure Audacity is open.


Using Audacity

Press the Record button and read the

poem below into the microphone.


Sandra’s seen a leprechaun,

Eddie touched a troll,

Laurie danced with witches once,

Charlie found some goblins’ gold.

Donald heard a mermaid sing,

Suzy spied an elf,

But all the magic I have known,

I’ve had to make myself.

When finished, press the Stop button.

Using Audacity


Two tracks will

appear in your

Audacity window.

Tracks are

graphical

representations of

the sound waves.

The two tracks

shown indicate

that the audio was

created in stereo.

Using Audacity


●Click on Effect.

●Select Leveller from the list.

Using Audacity

Saving an Audio File

Can save as an Audacity Project

Saved as a Project

Can open and edit individual tracks and added

components of an audio file

Cannot be played on standard computer audio players

Can save as a standard audio file

Exported

Compresses all tracks into a single track

Cannot be reopened to be edited

Can be played on standard computer audio players


Using Audacity


Click on File

Select Export

Select the location specified by your instructor.

Enter Magic as the file name.

Set the Save as Type to WAV.

Click Save.


Using Audacity


You will then be asked to enter data about the

audio file.

Enter your name next to Artist Name.

Click Ok.


Using Audacity

Open the file MoonLanding.mp3.


The file is the

communication

between the Apollo 11

and Mission Control

before and after Neil

Armstrong steps onto

the Moon’s surface.

Using Audacity

Locate the Tool Selector toolbar.

Click on the Selection Tool.

Listen to the audio and select the portion of

the audio where Neil Armstrong says “That’s

one small step for man, one giant leap for

mankind.”

The phrase is around the 3:30 area of the clip.


Using Audacity


“That’s one small step for man, one giant leap for mankind.”

The selected clip

should just be a

small portion of the

original sound clip.

Using Audacity

Trimming the Clip

We want to trim away everything outside of the

selected area.

From the Editing Toolbar, select the Trim tool.


Using Audacity


Finishing the clip

When we cut away the excess sound clip, the

selected clip is still almost 3 minutes into the sound

clip.

Using Audacity

From the Tool Selection toolbar, select

the Time Shift tool.


Drag the clip to

the far left of the

time line.

Using Audacity


Click the Playback button to make sure

that only the selected clip plays, and that

it plays immediately at the start of the

clip.

Export the audio file as

MoonLanding.wav

Podcasting

Media distributed over the internet via syndicated

download.

Podcasting is not limited to iPod. The concept was

conceived by Apple.

Podcasts can be viewed on computers, iPods, or

PDAs.

Podcasts allow visitors subscribe and automatically

download audio clips and listen to them offline.


Podcasting with Audacity

Audacity can be used for creating Podcasts

Podcasts audio files must be saved as an mp3.

Will need to install an update called Lame, which

will allow Audacity to create MP3 files.

When you try to export as an MP3 the first time, it

will give you the option of going to the download

page to install the update.



How Podcasts Work

Originally, broadcasts were

made at specific times.

You had to be available at

that time to receive the

broadcast.

Podcasting


•Podcasting utilizes a feature knows as RSS

(Really Simple Syndication).

•Used for content that is updated regularly.

•Requires you to use a program such as a Reader

to check for articles or a Receiver to download

podcasts.

•The Reader/Receiver automatically checks for

updates.

http://en.wikipedia.org/wiki/File:Feed-icon.svg

Podcasting Receivers


•Google Reader

•iTunes

•Juice

The Podcast Receiver will automatically check the RSS Channel page regularly

and download any new podcasts.


•Upload files to your server and update your RSS feed

page.

•Subscribers automatically receive the updates to their

devices


The RSS feed, or RSS Channel, is a special page that contains all the

Podcasts and is recognized by Readers and Receivers.

Visitors enter the URL of this page in their Podcast Receiver to

subscribe.

Available

podcasts

Podcast Channel

Creating the Podcast

To create your podcast:

Record your podcast.

Upload to your podcast server.

Update your podcast channel.

Your subscribers will automatically receive your

new podcast on their receiver.


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Digital & Interactive Media · Digital Audio Sound: Sound is simply waves of compressed air that move out from its source, similar to dropping a stone in water. Your ears are sensitive