Chapter 2 Communication and Internet Technologies

DATA COMMUNICATION AND NETWORKING

Data storage. Sound.

Sound Waves

OBJECTIVES:

• Show understanding that sound (music), pictures, video, text and numbers are stored in different formats

• Sound is an acoustic wave.
• The wave has analog values, meaning that it is continuous over amplitude and time.

Sound Waves

OBJECTIVES:

• Show understanding that sound (music), pictures, video, text and numbers are stored in different formats

• Sound travels as a wave.
• The amplitude of the wave controls how loud the sound is.
• The frequency controls the pitch.

Sound Waves

OBJECTIVES:

• Show understanding that sound (music), pictures, video, text and numbers are stored in different formats

• The image above shows how a wave changes to produce different sounds.

Digital audio

OBJECTIVES:

• Show understanding that sound (music), pictures, video, text and numbers are stored in different formats

• The sound we hear is analogue
• Sound is recorded using a microphone and converted to binary (digital) by software for storage and manipulation

Digital audio quality

OBJECTIVES:

• Show understanding that sound (music), pictures, video, text and numbers are stored in different formats

Factors that affect the quality of digital audio include:

• sample rate - the number of audio samples captured every second
• bit depth - the number of bits available for each clip
• bit rate - the number of bits used per second of audio