Computing Homework 11

Is 'real' sound analogue or digital?

• Analogue

• Digital

How is sound caused?

• By playing it through a hi-fi with speakers
• Vibrations travelling through air, water or metal.

Define what is meant by 'sampling'

• Height of the wave is measured, at intervals and stored as binary.

• The number of samples taken each second

•  The number of bits used per second of audio

• The amount of information required to describe one second of a sound.

Define the term 'sample rate'.

• Height of the wave is measured, at intervals and stored as binary.

• The number of samples taken each second

•  The number of bits used per second of audio

• The amount of information required to describe one second of a sound.

How do you calculate the bit rate of a digital audio file?

• Frequency x channels
• Frequency × bit depth × channels 
• Bit depth x channels
• Channels x 2 x bit depth

Which three factors affect the quality of an audio clip?

• Bit rate and bit depth
• Bit rate, bit depth and number of pixels
• Sample rate, analogue, number of pixels
• Sample rate, bit rate and bit depth

How does bit depth affect the quality of an audio clip and file size?

• The higher the bit depth, the higher the quality of the audio, but the larger the file size

• The more bits that are sampled the better the accuracy of the file but also the greater the file size. 

• Greater the frequency of the samples, the better the sound quality.

How does sample rate affect the quality of an audio clip and file size?

• The higher the bit depth, the higher the quality of the audio, but the larger the file size
• The more bits that are sampled the better the accuracy of the file but also the greater the file size. 
• Greater the frequency of the samples, the better the sound quality.

Sample rate is measured in....?

• Bits per second (bps)

• Hertz (Hz)

• Megabits per second (Mbps)

Identify the formula to calculate the bit rate for ONE second of audio

• = sample rate x bit depth x number of channels

• Width (in pixels) * Height (in pixels) * Colour depth