Data Representation - Sound

Digital sound always sounds better than analogue.

• False
• True

The most common sampling rate for sound files is 16 bit.

• False
• True

The most common sampling rate for sound files is 44.1 khz.

• True
• False

A microphone converts the changes in air pressure into voltage changes which are then digitised.

• True
• False

The following is true about sampling rates:

• They measure a number of snapshots of sound taken per second.
• They are not as important as bit rates.
• They are different for every song, depending on its loudness.

Sampling rate for CDs is different from the one used by DVDs.

• True
• False

DAC does this:

• Converts a binary stored version of a recording to voltage changes that speakers can reproduce.
• Takes voltage changes and digitises them for further processing and storage.
• Amplifies the sound and makes it digitally clean.

Identify a false statement:

• Higher bit rates usually improve the sound quality and result in smaller file size.
• Higher bit rates usually improve the sound quality but result in larger file size.
• To record a sound into binary format, ADC will be applied rather than DAC.

Which of the following is not a usual way of reducing sound file size:

• Erasing metadata and keeping recordings short.
• Using lossy compression.
• Using lossless compression.
• Reducing sampling rate or bit rate.

Lossy compression works by identifying sound frequencies that are not obvious and deleting them.

• True
• False