Data Representation: Text, Sound And Images: Understand How And Why A Computer Represents Sound, Including The Effects Of The Sample Rate And Sample Resolution (Copy)
| Concept | Computer Representation Of Sound |
|---|---|
| Why Sound Is Encoded | Computers only process binary data |
| Sound Nature | Sound is analogue (continuous) |
| Conversion | Analogue sound converted to digital |
| Process Name | Analogue-to-Digital Conversion (ADC) |
| Key Terms | Meaning |
|---|---|
| Sample | A single measurement of sound amplitude |
| Sample Rate | Number of samples taken per second |
| Sample Resolution | Number of bits used per sample |
| Bit Depth | Another term for sample resolution |
| Sample Rate | Details |
|---|---|
| Definition | Samples taken per second (Hz) |
| Common Rates | 44.1 kHz, 48 kHz |
| Effect On Quality | Higher rate = more accurate waveform |
| Effect On File Size | Higher rate = larger file |
| Sample Resolution | Details |
|---|---|
| Definition | Bits used to store each sample |
| Common Values | 8-bit, 16-bit |
| Effect On Quality | Higher resolution = more amplitude levels |
| Effect On Noise | Higher resolution reduces quantisation error |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Computer Science Full Scale Course
| Example Comparison | Low | High |
|---|---|---|
| Sample Rate | Fewer samples | More samples |
| Sample Resolution | Fewer bits | More bits |
| Sound Quality | Lower | Higher |
| File Size | Smaller | Larger |
| Analogue vs Digital | Difference |
|---|---|
| Analogue | Continuous waveform |
| Digital | Discrete binary values |
| Quantisation | Explanation |
|---|---|
| Meaning | Rounding analogue values to nearest digital level |
| Error | Difference between actual and stored value |
| Reduction | Increase sample resolution |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Computer Science Full Scale Course
| Trade-Offs | Impact |
|---|---|
| Higher Sample Rate | Better quality, larger file |
| Higher Resolution | Better accuracy, more storage |
| Lower Values | Smaller files, reduced quality |
| Examiner Keywords | Use In Answers |
|---|---|
| Sample Rate | Accuracy over time |
| Sample Resolution | Accuracy of amplitude |
| Quantisation Error | Sound distortion |
| ADC | Conversion process |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Computer Science Full Scale Course
| Common Examiner Traps | How To Avoid |
|---|---|
| Confusing rate and resolution | Define both clearly |
| Ignoring file size | Mention storage impact |
| Missing ADC | Always name conversion |
| Saying “better quality” only | Explain why |
| One-Line Summary | Exam-Perfect Statement |
|---|---|
| Sound Representation | Analogue sound sampled and digitised |
| Sample Rate | Controls time accuracy |
| Sample Resolution | Controls amplitude accuracy |
Written and Compiled By Sir Hunain Zia (AYLOTI), World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Computer Science Full Scale Course