2. Dr. CK Tan, UMS 2
MULTIMEDIA COMPONENTS
Graphics
Animation
Video
Audio
Cds
3. Dr. CK Tan, UMS 3
AUDIO
Audio can be any form of recorded
voice or music or both
• Convey meaning – provide extra
channel of info to audience
• Different learner, different learning
strategies (live web lecture)
• Add sense of realism, sensation
• Directing attention to important events
• Facilitate communication
Why is audio used?
4. Dr. CK Tan, UMS 4
Voice
• Voice is analogue waves
• Voice is audio narration (whispers,
cries, shouts, etc)
• Expressed in decibels (db)
dB Watts Examples
195 25-40m Saturn rocket
170 100,000 Jet engine
70 0.00001 Voice
30 0.000000001 Whispers
5. Dr. CK Tan, UMS 5
Terms related to audio
• Volume is peak of the
wavelength
• Frequency is the distance
between the audio waves
• If 1000 waves are repeated in a
second 1000 Hz or 1 KHz
• Sampling is the process of
digitizing analogue signals
6. Dr. CK Tan, UMS 6
• There are 3 main sampling
rate for audio 11, 22.05
and 44.1 KHz
• Sample size is either 8 or 16-
bit
• Channel is either stereo or
mono
Terms related to audio
7. Dr. CK Tan, UMS 7
Comparison
Comment Sampling
rate
Sample
size
Bytes
CD Quality 44 KHz 16 bit 10 MB
Close to CD 22 KHz 16 bit 5 MB
Voice
quality
11 KHz 16 bit 2.5 MB
8. Dr. CK Tan, UMS 8
Audio File Calculation
Formula
File size = sampling rate X recording
duration in second X (Sample size
in bits/8) X number of channels
Example: 10 seconds of recording
at 22.05 kHz, 8 bit resolution and
mono channel
= 22050 x 10 x (8/8) x 1
= 220500 bytes
9. Dr. CK Tan, UMS 9
Importance of audio for education
Audio gives student feedbacks on activity that is done online.
Student generated recordings which may be used as part of a
learner activity or to record evidence.
Audio can serve as evidence or primary sources of
information for activities. E.g. recorded audio of respondents
Recorded public lectures can be used as teaching materials
and can be replayed numerous times as learning activities.
Live online discussions can be conducted via audio tools and
platforms between two or more people and this facility is
frequently used for distance learning.
Audio source materials from the past and present can provide
rich descriptions of past events.
