1. Sound technology

2. Basics of Sound
Sound is perhaps the most sensuous element of multimedia
Types of sound in multimedia
speech
music
special effects
mood-setting background sounds
etc

3. The power of sound
Although sound is rarely the main content in a multimedia production, remember that
Sound can make the difference between an ordinary multimedia presentation and a professionally spectacular one
Misuse of sound can wreck your project

4. Sound in Multimedia
To use sound in multimedia you will not need special knowledge about harmonics, intervals, sine waves or notation
However, you should know the following:
How to make sounds
How to record and edit sounds on your computer
How to incorporate sounds into your multimedia work

5. Digital audio Digital audio means digitized sound
The source can be whatever, natural or prerecorded
Digitized sound is sampled sound: every nth fraction of a second, a sample of sound is stored as digital information (bits and bytes)

6. Digital audio Sampling rate: how often a sample is taken
Sample size: the amount of information that is stored about each sample
Typical sampling frequencies are 44,1 kHz, 22,05 kHz and 11,025 kHz
Sample sizes are either 8 bits or 16 bits
It is impossible to reconstruct the original waveform if the sampling frequency is too low!

7. Editing digital recordings
Trimming: removing dead air and blank space
Splicing and assembly: remove the extraneous noises and assemble longer recordings from many shorter ones
Volume adustments: provide a consistent volume level
Format conversion: convert your file to a proper format
Resampling or downsampling: if using lower rates and resolutions, but 16-bit sampling rate (to save disk space)

8. Editing digital recordings
Fade-ins and fade-outs: to gradually fade-in or –out if needed
Equalization: modify recording’s frequency content to sound brighter or darker
Time stretching: alter the length without changing the pitch
Digital Signal Processing (DSP) (reverberation, multitab delay, chorus etc)
Reversing sounds

9. Audio file formats
There are dozens of them, created for different purposes over the years
Nowadays the most used digital audio formats are mp3 (computers, portable mp3 players, some DVD players), wma (Windows-only audio format) and rm/ram (RealAudio format).
Other formats: .aiff, .mod, .snd, .mid, .wav

10. Adding sound to your multimedia project
Decide what kind of sound is needed and where you’ll use them
Acquire source material
Edit the sounds to fit your project
Test the sounds to be sure they are timed properly

11. Stereo recording

12. Dynamic microphone

13. Capacitor microphone

14. High sound pressure possible
Sensitive, low sounds
General microphone
Phantom power
Attenuates handling sounds
Sensitive to handling sounds
Effects, speech, music
Interview, song, speech, percussions, music

15. Sphere Heart, cardioid Shotgun Eight

21. File size, Bytes
Duration of sound in seconds

22. Basic Windows sound