Sound

​Do now:

​

​ 1. Log in

2. ​Go to Paper 2​ - Binary and Hex > Sound

3. Complete Do Now

​Big Question:

​How do we convert analogue sounds into digital files?

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How we do calculate sound sample sizes?

​Key words: Sample rate, Bit Depth, Analogue to Digital Conversion, Sampling

​Turn & Talk:

​How can we capture sound digitally?

​

Person A: I think to capture sound digitally you can....​

​

Person B: I agree / disagree / would like to ​

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​Analogue to Digital Converter

​Sample Rate

(Speed)​

​Sample Rate

(Speed)​

​Bit Depth

(Detail)​

​+

​

​Sample Rate:

​How often (frequency) you record the amplitude of a sound wave.

The more often you record a sample the smoother the playback will sound​

​Sample Rate

https://www.youtube.com/watch?v=hRhVb6iRArg

​Questions ahead...

Multiple Choice

The more often you record a sample the ___________ the playback will sound

• Lower

• Worse

• Louder

• Smoother

Multiple Choice

The number of samples taken per second is called

• sample rate

• frequency rate

• analogue rate

• digital conversion rate

Multiple Choice

A typical CD is recorded at

• 4.1 Hz

• 410 Hz

• 41004 Hz

• 44,100Hz

​Bit rate examples

https://www.youtube.com/watch?v=ubCMI3Jq6e4​

​Questions ahead...

Multiple Choice

The amount of bits allocated per sample is called the

• bit rate

• sample rate

• bit depth

• bit sample

Multiple Choice

The bit rate is calculated using..

• Sampling Frequency x Sample Size

• Whole sample size x sample depth

• sample height x width

​Calculating file size

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculate the file size in bits for a 0.5 minute sound recording that has used a sample rate of 500 Hertz (Hz) and a sample resolution of 4 bits.  

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculate the file size in bits for a 0.5 minute sound recording that has used a sample rate of 500 Hertz (Hz) and a sample resolution of 4 bits.  

​

30(s) x 500(Hz) x 4(bits)​

​

​Calculating file size

​Size of sample =

(number of samples per second) x (number of bits per sample) x (length of sample in seconds)

sample rate x bit depth x time​

​Calculate the file size in bits for a 0.5 minute sound recording that has used a sample rate of 500 Hertz (Hz) and a sample resolution of 4 bits.  

​

30(s) x 500(Hz) x 4(bits)​

=

60,000 bits​

​

​Questions ahead...

Multiple Select

The higher the sample rate and bit depth...

• The smaller the file size

• The bigger the file will be

• The lower the quality

• The higher the quality

Multiple Choice

The calculation to get the file size is...

• sample rate(bits) x bit depth(Hz) x time(s)

• sample rate(Hz) x bit depth(bits) x time(hours)

• sample rate(s) x bit depth(Hz) x time(s)

• sample rate(Hz) x bit depth(bits) x time(s)

​Go to class notebook: