Sound and Compression

An analogue to digital converter takes the analogue singal from a microphone and converts it to a rapid sequence of digital values. This process is called...

• tasting

• sampling

• measuring

• frequency

Which of the following are sound file types?

• MP3

• FLAC

• AAC

• JPEG

File compression is used to...

• make file sizes smaller

• stop people pirating music

• to prevent files being edited

• annoy people

File compression can be lossy or lossless. Lossy compression works by removing or simplifying some of the detail from image or sound data so that the file becomes smaller. How does a lossless compression reduce file size?

• It removes and throws away some of the information.

• It converts repeating values into an encoded form that takes less space.

• It relies upon a link to the internet.

Reducing file size has the advantages of...

• Streaming over the internet is faster for a given bandwidth

• Web pages using smaller image files will load quicker

• Less storage space is taken up on devices using those files

• Decompressing a file increases load on the CPU.

What does the bit rate of a sampled sound refer to?

• The number of bits used for 1 second of audio

• The number of bits used for every sample

• The final file size of the sampled sound

• The speed at which the sampled sound is played back

What is the process called for  converting analogue sound into binary (digital format)?

• Conversions
• Sampling
• Bit Rate
• Converting

Increasing the sample rate means the analogue recording is sampled more often?

• True

• False

What is measured when the wave is sampled?

• Amplitude

• Hertz

• Bit rate

• Frequency

Define the term 'sampling'.

• Snapshots of sound are taken at regular intervals
• The number of samples taken each second
•  The number of bits used per second of audio
•  The number of bits available for each clip